Merge pull request #19 from edx/vik/add-docs

Vik/add docs
Merge pull request #20 from edx/vik/add-docs

Add in better notes to readme.md
Merge pull request #21 from edx/vik/add-docs

Vik/add docs
don't need build-essential twice
add a few extra steps
Merge pull request #22 from natea/patch-1

don't need build-essential twice
Merge pull request #23 from natea/patch-2

add a few extra steps
Merge remote-tracking branch 'origin/master' into vik/add-docs

Conflicts:
	docs/installation/installation_overview.rst