Restructure for topics/conventions/ docs

Add index.rst for conventions
Add the Salt Release Process to the documentation
Add conventions to the TOC
Merge pull request #5808 from basepi/releasedocs

Add the Salt Release Process to the documentation
fixing apt.mod_repo to work on ubuntu < 12.04
Merge pull request #5812 from nevins-b/develop

fixing apt.mod_repo to work on ubuntu < 12.04
Don't ignore environment variables pointing to valid configuration files. Fixes saltstack/salt-cloud#661

`salt.config.load_config()` cannot be hard-coded to use only the master configuration file as the default configuration file path to know if the user has passed any configuration file in the CLI tool or not.
To fix this, `default_path` was added. This way, the minion config or client config or even the salt cloud config can say which is the expected default path of the configuration file and properly load config from environment variables.
pillar: allow include to provide a key within which to next
pillar: allow include to provide a key within which to nest -- bugfix
pillar: allow include to provide a key within which to nest -- another bugfix
Merge pull request #5816 from mgwilliams/pillar-include-defaults

nesting for pillar includes
Fix more class refs to the Shell class
Tie off some minor additions here
Remove the evil dash of doom

Good catch, @s0undt3ch!  =)
Merge pull request #5818 from basepi/releasedocs

Remove the evil dash of doom
Fix traceback on non-yum systems

3b8b6de added yum.rpmtrans.RPMBaseCallback as a base class for
the _YumLogger class, which causes tracebacks on non-yum systems. This
commit fixes that by only creating this class if the yum python
interface is successfully imported.
Merge pull request #5819 from terminalmage/quickfix

Fix traceback on non-yum systems
Make openSUSE <12.1 use sysvinit for service mgmt

This fixes #5801 by checking the major release of the distro, if the
minion is openSUSE.
Merge pull request #5821 from terminalmage/issue5801

Make openSUSE <12.1 use sysvinit for service mgmt
Resolve Issue #5822