Make the build system automatically build the C# Api assemblies to be shipped with the editor.
Make the editor, editor player and debug export templates use Api assemblies built with debug symbols.
Always run MSBuild to build the editor tools and Api assemblies when building Godot.
Several bugs fixed related to assembly hot reloading and restoring state.
Fix StringExtensions internal calls not being registered correctly, resulting in MissingMethodException.
- Now there is only one solution that contains both GodotSharp and GodotSharpEditor project. Previously we had one solution for each project
- GodotSharpEditor reference GodotShatp with a 'ProjectReference'. Previously it was a 'Reference' to the assembly
- This also simplifies the command line option to generate this solution: 'godot --generate-cs-api <OutputDir>'
Using `misc/scripts/fix_headers.py` on all Godot files.
Some missing header guards were added, and the header inclusion order
was fixed in the Bullet module.
