fix EOLs
add suffix to project name
add gitattributes, gitignore, makefile
remove some non-standard behavior

* don't handle dates and datetimes.
* don't silently return an empty dict when the object is not
  serializable.
* don't fall back to calling a 'toDict' func attr to get a dict object.
* don't fall back to serializing the object's attr dict.
improve readability

* enable "extra whitespace" mode.
* fix typo in handling that mode.
dumps: add arg default

use it as a JSON-serializable object.
dumps: add arg allow_nan