Stable Build 5009

For mappers:

• Add attachToSolid attribute to spikes to allow preventing them from attaching (map editor support pending).
• Add the ability to exclude specific tileset IDs from being ignored via an ignoreExceptions attribute in the tileset XML.

Tweaks:

• Use relative symlinks when installing Everest. This allows fresh installs to be moved safely after installing Everest without breaking the link to vanilla.

Bugfixes:

• Fix issues with dash trails for large sprites or long player hair.
• Fix mods sometimes being falsely recognized as out of date by the auto-updater.