Move sorting package names to GUI related code

This commit reduces set->list->set ping-pong by sorting package lists
just before displaying them in quick panels.

package_control/commands/disable_package_command.py

@@ -35,10 +35,10 @@ def list_packages(self, manager):
             A list of package names to add to the quick panel
         """
 
-        packages = manager.list_all_packages()
-        ignored = PackageDisabler.ignored_packages()
-        ignored.add('Package Control')
-        return sorted(set(packages) - ignored, key=lambda s: s.lower())
+        return sorted(
+            manager.list_all_packages() - PackageDisabler.ignored_packages() - {'Package Control'},
+            key=lambda s: s.lower()
+        )
 
     def on_done(self, manager, package_name):
         """

package_control/commands/existing_packages_command.py

@@ -32,7 +32,7 @@ def run(self):
         url_pattern = re.compile(r'^https?://')
 
         package_list = []
-        for package in self.list_packages(manager):
+        for package in sorted(self.list_packages(manager), key=lambda s: s.lower()):
             if package in default_packages:
                 description = 'Bundled Sublime Text Package'
                 installed_version = default_version

package_control/commands/list_packages_command.py

@@ -38,7 +38,7 @@ def list_packages(self, manager):
             A list of package names to add to the quick panel
         """
 
-        return manager.list_packages()
+        return sorted(manager.list_packages(), key=lambda s: s.lower())
 
     def on_done(self, manager, package_name):
         """

package_control/commands/list_unmanaged_packages_command.py

@@ -27,4 +27,5 @@ def list_packages(self, manager):
         ignored_packages = load_list_setting(settings, 'unmanaged_packages_ignore')
         ignored_packages |= load_list_setting(settings, 'installed_packages')
 
-        return sorted(set(manager.list_packages()) - ignored_packages, key=lambda s: s.lower())
+        packages = manager.list_packages() - ignored_packages
+        return sorted(packages, key=lambda s: s.lower())

package_control/package_cleanup.py

@@ -79,7 +79,7 @@ def run(self):
 
         # Remove non-existing packages from ignored_packages list.
         orphaned_ignored_packages = self.ignored_packages() - found_packages \
-            - set(self.manager.list_default_packages())
+            - self.manager.list_default_packages()
 
         if in_process or orphaned_ignored_packages:
             self.reenable_packages({self.ENABLE: in_process | orphaned_ignored_packages})
@@ -398,7 +398,7 @@ def install_missing_packages(self, found_packages):
 
         # Drop remaining missing packages, which seem no longer available upstream,
         # to avoid trying again and again each time ST starts.
-        missing_packages = installed_packages - set(self.manager.list_packages())
+        missing_packages = installed_packages - self.manager.list_packages()
         if missing_packages:
             self.manager.update_installed_packages(remove=missing_packages)
 

package_control/package_creator.py

@@ -34,7 +34,7 @@ def run(self):
         Shows a list of packages that can be turned into a .sublime-package file
         """
 
-        self.packages = self.manager.list_packages(unpacked_only=True)
+        self.packages = sorted(self.manager.list_packages(unpacked_only=True), key=lambda s: s.lower())
         if not self.packages:
             show_message('There are no packages available to be packaged')
             return

package_control/package_manager.py

@@ -756,7 +756,7 @@ def list_packages(self, ignored_packages=None, unpacked_only=False):
             Only list packages that are not inside of .sublime-package files
 
         :return:
-            A list of all installed, non-default, non-library, package names
+            A set of all installed, non-default, non-library, package names
         """
 
         packages = set(list_sublime_package_dirs(sys_path.packages_path()))
@@ -766,33 +766,33 @@ def list_packages(self, ignored_packages=None, unpacked_only=False):
             packages -= ignored_packages
         packages -= set(list_sublime_package_files(sys_path.default_packages_path()))
         packages -= {'Binary', 'Default', 'Text', 'User'}
-        return sorted(packages, key=lambda s: s.lower())
+        return packages
 
     def list_default_packages(self):
         """
         Lists all builtin packages shipped with ST
 
         :return:
-            A list of default package names
+            A set of default package names
         """
 
         packages = set(list_sublime_package_files(sys_path.default_packages_path()))
         packages -= {'Binary', 'Default', 'Text', 'User'}
-        return sorted(packages, key=lambda s: s.lower())
+        return packages
 
     def list_all_packages(self):
         """
         Lists all packages on the machine
 
         :return:
-            A list of all package names, including default packages
+            A set of all package names, including default packages
         """
 
         packages = set(list_sublime_package_dirs(sys_path.packages_path()))
         packages |= set(list_sublime_package_files(sys_path.installed_packages_path()))
         packages |= set(list_sublime_package_files(sys_path.default_packages_path()))
         packages -= {'Binary', 'Default', 'Text', 'User'}
-        return sorted(packages, key=lambda s: s.lower())
+        return packages
 
     def predefined_packages(self):
         """