Merge branch 'cursor_messages'
None as database/server now supported (None user and password were already supported)
default values changed to None
Merge branch 'empty_db'

Conflicts:
	pytds/dbapi.py
merge bug fixed
prevented recordtype/namedtuple fails when column name is not a valid identifier
Merge remote branch 'upstream/master'

Conflicts:
	pytds/dbapi.py
recordtype-based rows now support indexed access
Merge pull request #30 from VFLashM/master

namedtuple/recordtype rows corner-cases fixes, indexing support