Updated to MonoGame 3.6 + Directory refactor

- Barotrauma's projects are in the Barotrauma directory
- All libraries are in the Libraries directory
- MonoGame is now managed by NuGet, rather than referenced from the installed files (TODO: consider using PCL for easier cross-platform development?)
- NuGet libraries are not included in the repo, as getting the latest versions automatically should be preferred
- Removed Content/effects.mgfx as it didn't seem to be used anywhere
- Removed some references to Subsurface directory
- Renamed Launcher2 to Launcher

Libraries/SharpFont/Makefile

@@ -0,0 +1,16 @@
+XBUILD              := xbuild
+XBUILDFLAGS_RELEASE := /p:Configuration=Release
+XBUILDFLAGS_DEBUG   := /p:Configuration=Debug
+
+SOLUTION            := Source/SharpFont.sln
+
+release:
+	$(XBUILD) $(XBUILDFLAGS_RELEASE) $(SOLUTION)
+debug:
+	$(XBUILD) $(XBUILDFLAGS_DEBUG) $(SOLUTION)
+clean:
+	$(XBUILD) $(XBUILDFLAGS_DEBUG) $(SOLUTION) /t:Clean
+	$(XBUILD) $(XBUILDFLAGS_RELEASE) $(SOLUTION) /t:Clean
+
+.SUFFIXES:
+.PHONY: release debug clean