first draft
Merge remote-tracking branch 'upstream/develop' into ebuild_enhanced

Conflicts:
	salt/states/portage_config.py
some fixes
merge fix
other merge fix
added check_extra_requirements function
check_extra_requirements documentation
some fixes
fixes
doc fix
overlay->repository
Update `salt.config` to use `salt.utils.fopen` instead of `open`
Update `salt.crypt` to use `salt.utils.fopen` instead of `open`
Update `salt.fileserver.gitfs` to use `salt.utils.fopen` instead of `open`
Update `salt.grains.extra` to use `salt.utils.fopen` instead of `open`
Update `salt.master` to use `salt.utils.fopen` instead of `open`
Update `salt.modules.config` to use `salt.utils.fopen` instead of `open`
Update `salt.modules.grains` to use `salt.utils.fopen` instead of `open`
Update `salt.modules.img` to use `salt.utils.fopen` instead of `open`
Update `salt.modules.kmod` to use `salt.utils.fopen` instead of `open`