add parse_match tests for atoms with subslots
simplify similar exception test cases for parse_match
add support for "*/*::repo" wildcard patterns for atoms

Pkgcore already supported "*::repo" but that isn't supported by portage
while the "*/*::repo" format is. This allows cross-compliance for people
using similar patterns in their config files to mask, unmask, or keyword
entire repos or for other related usage.
simplify duplicate conditional case for parse_match
travis-ci: make sure pkgcore tests are run, not snakeoil
fix compatibility import namespace issues
pmerge: add -S shortcut for --source-only
remove duplicate repo list creation during config generation
drop old EBD_WRITE_FD/EBD_READ_FD compat
remove unnecessary ACCEPT_LICENSE default

The system default should be set already via make.globals.
describe formatting marks for masked/keyword cases
allow PKGDIR and DISTDIR env settings to override defaults as well

We need to add a proper, unified way to load env settings for overrides.
add proper eapi support to fake packages
use dict comprehensions instead of constructors

Since we're dropping python2.6 support (it's no longer maintained
upstream) we might as well use some syntactical sugar supported in later
versions.
strip trailing slashes from doins arguments

Without stripping slashes subdirs aren't created properly in all cases,
e.g. dev-vcs/gitolite-3.6 fails to install due to this.