* Replaced all assert statements with yAssert, which prints an error message
and quits on failure, but does nothing when compiling with -d:release.
* Implemented and used internalError for better discovery of internal bugs.
Fixes#8.
* Made RawYamlStream able to raise YamlStreamError, which might primarily be
useful for user-defined serialization
* Properly encapsulate RangeError coming from int/uint serialization on 64bit
machines in YamlStreamError.
* Some minor style improvements
* fieldPairs() already handles variant objects fine. decided not to
go further along the way of identifying object variants by their
discriminants in tag URIs.
* variant objects are now supported just like normal objects.
* 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
* Added PresentationOptions object; merged PresentationStyle,
indentationStep and NewLineStyle in it
* Updated signatures of relevant procs
* Implemented user-defined newline style in presenter
* Added serialization.txt to doc
* Fixed rendering problem in api.txt
* Use explicit tag when ref type renders to a scalar that can be
parsed to !!null
* Added test cases for this ref type fix