* Renamed some symbols for consistency, fixes#6:
- yamlStartSequence -> yamlStartSeq
- yamlEndSequence -> yamlEndSeq
- yamlStartDocument -> yamlStartDoc
- yamlEndDocument -> yamlEndDoc
- yTagMap -> yTagMapping
* Improved code formatting at some places
* Fixed code documentation at some places
* Added generic objects to TODO list
* Removed obsolete parsing tests, these are superseeded
by yaml-dev-kit test suite integration
* Made TagLibrary a ref object
* Started writing fastparse.nim, a parser aimed to deliver
much faster speeds than the current implementation. It
currently is only able to parse block content
* Added YamlWarningCallback that may be used to capture
parser warnings
* Removed yamlWarning as event kind
* Replaced checks for well-formedness in presenter with asserts
* Added checks for JSON compatibility of YamlStream in presenter
* Added proper type hints for special float values in
serializer to be able to check for them in the presenter