pinspect: shorten repo query subcommands

Specifically change 'get_repositories' to 'get_repos' and
'get_repositories_path' to 'get_repo_path', portageq already uses the
shortened names.
pinspect: add stable_{forced,masked}_use subcmds for profiles

Allows users to easily see the difference between stable and unstable
profile usage.

Note that it doesn't make sense to automatically determine which to show
since that relates to a pkg's KEYWORDS value and the ACCEPT_KEYWORDS
setting for a local machine's configuration.
pebuild: allow atom or ebuild file arguments

Now you can also pass an ebuild file directly to pebuild to operate on
(as you might be used to from using portage's ebuild command). Note that
it is currently required for the ebuild to be in a configured
repository.

Fixes #14.
pebuild: tweak argument description to note multiple types allowed
pebuild: don't print a newline before each selected phase
news: note additions of stable_masked_use and stable_forced_use subcmds
drop extra variable usage when eval-ing defined functions

Also simplify function sourcing failure messages for banned and
deprecated EAPI functions.
indentation consistency
minor tweaks for failure messages using ${T}
minor variable name and scope changes
__get_func_code: don't echo a newline when a function isn't defined
eapi6: initial EAPI 6 profile stub
eapi6: initial get_libdir implementation

Basically a renamed version of the internal implementation.

X-Gentoo-Url: https://bugs.gentoo.org/show_bug.cgi?id=463586
eapi6: initial eapply implementation (todo)

X-Gentoo-Url: https://bugs.gentoo.org/show_bug.cgi?id=463768
eapi6: initial eapply_user implementation

X-Gentoo-Url: https://bugs.gentoo.org/show_bug.cgi?id=475288
eapi6: initial PATCHES support in src_prepare

X-Gentoo-Url: https://bugs.gentoo.org/show_bug.cgi?id=463692
eapi6: mark dohtml as deprecated
eapi6: ban einstall

X-Gentoo-Url: https://bugs.gentoo.org/show_bug.cgi?id=524112
eapi6: econf passes --docdir and --htmldir args

X-Gentoo-Url: https://bugs.gentoo.org/show_bug.cgi?id=468202
eapi6: initial einstalldocs implementation

This also adds directory support and the ability to explicitly disable
the install of docs by setting empty variables.

Finally, the default src_install function now calls einstalldocs.

X-Gentoo-Url: https://bugs.gentoo.org/show_bug.cgi?id=459692
X-Gentoo-Url: https://bugs.gentoo.org/show_bug.cgi?id=481980
X-Gentoo-Url: https://bugs.gentoo.org/show_bug.cgi?id=463736