Updated to work with nim 0.20

- Attempt to fix deprecated this:self pragma by injecting self to methods and properties (needs more testing)
- Changed import headers to use / (slash) instead of . (period)
- Fixed object branch in godotapigen.nim
- Fixed deprecated nimNode.ident with nimNode.strVal

Fix toGodotName function

Consider procCall calls as special cases, otherwise it gives problems in _init function

Fix infinite recursive call in Godot 3.2

godot/core/rids.nim

@@ -2,7 +2,7 @@
 
 import hashes
 
-import godotcoretypes, internal.godotinternaltypes, gdnativeapi
+import godotcoretypes, internal/godotinternaltypes, gdnativeapi
 
 proc initRID*(): RID {.inline.} =
   getGDNativeAPI().ridNew(result)