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/variants.nim

@@ -1,9 +1,9 @@
 import tables, hashes
 
 import godotcoretypes
-import internal.godotinternaltypes, internal.godotvariants,
-       internal.godotstrings, internal.godotdictionaries,
-       internal.godotarrays
+import internal/godotinternaltypes, internal/godotvariants,
+       internal/godotstrings, internal/godotdictionaries,
+       internal/godotarrays
 
 type
   Variant* = ref object