added test that shows has_page_add_permission fails with target
fixed site not being defined
added pyflakes test
fixed pyflakes issues
Merge remote-tracking branch 'origin/develop' into pyflaked

Conflicts:
	cms/cms_toolbar.py
	cms/tests/admin.py
	cms/tests/nested_plugins.py
	cms/tests/no_i18n.py
	cms/tests/plugins.py
	cms/tests/rendering.py
	cms/tests/reversion_tests.py
	cms/tests/toolbar.py
Merge pull request #2776 from ojii/pyflaked

Fixed all pyflake warnings, added pyflake test, added pyflake develop.py command