test against postgresql and mysql databases as well

- turn off mysql till #29 passes
update changes
drop python 2.6 tests
add xfail for failing testcase
xfail on proper condition
Merge branch 'dbfixtures'

- closes #21

Conflicts:
	CHANGES.rst
	pyramid_fullauth/views/basic/login.py
	pyramid_fullauth/views/basic/register.py
	pyramid_fullauth/views/social.py