Move FatalError to its own header.

untwine/Common.hpp

@@ -1,13 +1,5 @@
 #pragma once
 
-#ifdef _WIN32
-#include <Windows.h>
-#include <io.h>
-#else
-#include <unistd.h>
-#include <sys/mman.h>
-#endif
-
 #include <stdint.h>
 #include <array>
 #include <limits>
@@ -18,6 +10,7 @@
 #include <pdal/SpatialReference.hpp>
 #include <pdal/util/Bounds.hpp>
 
+#include "FatalError.hpp"
 #include "FileDimInfo.hpp"
 
 namespace untwine
@@ -29,13 +22,6 @@ const int CellCount = 128;
 using PointCount = uint64_t;
 using StringList = std::vector<std::string>;
 
-class  FatalError : public std::runtime_error
-{
-public:
-    inline FatalError(std::string const& msg) : std::runtime_error(msg)
-        {}
-};
-
 struct Options
 {
     std::string outputName;

untwine/FatalError.hpp

@@ -0,0 +1,15 @@
+#pragma once
+
+#include <stdexcept>
+
+namespace untwine
+{
+
+class  FatalError : public std::runtime_error
+{
+public:
+    inline FatalError(std::string const& msg) : std::runtime_error(msg)
+        {}
+};
+
+} // namespace untwine

untwine/windows/stringconv.hpp

@@ -2,6 +2,8 @@
 
 #include <Windows.h>
 
+#include <FatalError.hpp>
+
 namespace untwine
 {
 namespace os