Various compilation speed improvements

- Move GLHeaders into Main.h to be precompiled
- Moved Mus2Mid and ZReaders stuff out of thirdparty and into the main sources as they are using Main.h (for MemChunk), which is pretty hefty and meant to be precompiled
- The biggest change is splitting up the sol3 lua exports into multiple files where appropriate. This goes against the advice in the sol3 documentation (to put everything in one cpp file) but for me splitting it over multiple gives a massive compile speed improvement as parallel multi-core compilation can be better utilised. This change *may* cause compilation time to increase on older CPUS with less cores but hopefully it won't be too bad

These changes bring full rebuild time (on my Ryzen 7 7700X) down from ~35 seconds to ~22 seconds

src/Application/Main.h

@@ -76,6 +76,7 @@ using u64 = uint64_t;
 #include "Utility/Structs.h"
 #include "General/Log.h"
 #include "Utility/MemChunk.h"
+#include "OpenGL/GLHeaders.h"
 // clang-format on
 
 #endif // __MAIN_H__

src/CMakeLists.txt

@@ -19,6 +19,7 @@ file(GLOB_RECURSE SLADE_SOURCES CONFIGURE_DEPENDS
 	TextEditor/*.cpp
 	UI/*.cpp
 	Utility/*.cpp
+	ZReaders/*.cpp
 )
 
 # Lua/Scripting sources if not excluded

src/MainEditor/Conversions.cpp

@@ -33,8 +33,8 @@
 #include "Conversions.h"
 #include "Archive/Archive.h"
 #include "Archive/ArchiveEntry.h"
-#include "thirdparty/mus2mid/mus2mid.h"
-#include "thirdparty/zreaders/i_music.h"
+#include "Mus2Mid.h"
+#include "ZReaders/i_music.h"
 
 using namespace slade;