Added initial slot support to ebuild functions

Added slot support for ebuild.install, ebuild.update, ebuild.remove,
ebuild.purge
move documenatation generation to bottom

Installing Salt is required for auto-generated
module documentation.  Also mentioned about Sphinx
installation using pip.
Add param persist to states.kmod
fix #3403
Update Windows Installer location.
Add a "manage.status" runner that gives a combined up/down report

It would be nice to get the up/down state of all salt minions in a
single command.  The current runners make it so that two commands
are needed to get this information

This adds a new "manage.status" runner that will print a report of
the up/down state in a consumable format (YAML).  It also refactors
the up() and down() runners to use a common code path
Bugfix for commit 1d5ce52

If status() returns an empty dict, up() and down() will throw
exceptions, since None is not iterable.
Merge pull request #3408 from 0xDEC0DE/develop

Add a "manage.status" runner that gives a combined up/down report
Conform with the dict return type for 'salt.modules.grains.item'.
One more `grain.item` fix to comply with new dict output.
Fix supervisor test.
Merge pull request #3413 from s0undt3ch/develop

Fix tests.
Merge pull request #3392 from shadowfax-chc/ebuild-improv2

Added initial slot support to ebuild functions
Merge pull request #3400 from viktorkrivak/develop

Add param persist to states.kmod
minor formatting change
Merge pull request #3399 from baijum/doc

move documenatation generation to bottom
Merge pull request #3404 from giantlock/develop

fix #3403
Removed docs for non-existent module

Fixes #3384
Removed nonexistent module docs from TOC
Removed placeholder doc