Update doc/install/databases.md

Update docs for PostgreSQL installation

TYPO #1870

TYPO

Merge branch 'public_submission_milestones_for_mr' of https://github.com/piffio/gitlabhq into piffio-public_submission_milestones_for_mr

Conflicts:
	app/views/merge_requests/_form.html.haml

Refactor Satellite Code

When a MR belongs to a Milestone, show this information in the listing
with a small box telling the Milestone title.

Link to commit authors everywhere

gitolite's repositories folder symlinked patch

Fixes #1830

Fixes #1836

Conflicts:
	app/views/issues/_form.html.haml

Fix PostgreSQL setup instructions

The config skeleton for postgres is called `database.yml.postgresql`,
not `database.yml.postgres`.