Fix reference in setup.py to salve.util package

This is a reference to a no longer existing package, and therefore must be
discarded.
Moved most of setup tooling out of /setup/ dir

The Makefile and requirements are still there, lest they be mistaken for
requirements of the project itself. This allows users to download and install
by running on the setup.py file. Also separated build and upload setps in
Makefile.
Bumped version to 2.3.1
Merge branch 'bugfix/setuptools-fixes' into dev
Add a '--version' argument and necessary support

Had to move version string into salve.__version__ Rather than letting setup.py
be the custodian of this information, it is part of the salve package so that
the argparsing can pull it in correctly.
Merge branch 'feature/version-flag' into dev
Convert all markdown docs to reST

These conversions include several syntactic rewrites, but no major changes to
the content of the LICENSE, CHANGELOG, and README files. Also fixes setup.py to
draw upon these now documentation sources.
Merge branch 'documentation/md-to-rst' into dev
Merge branch 'dev' into stable

Conflicts:
	README.rst

Fixed by updating RST to point at stable-branch badges