Check for CSS files in Mahara sanity check

[Aaron Wells]

Since we removed the compiled CSS files from Mahara's git repo, if you just check out the git code and try to run it, you'll be missing all the styles.

We can (and should) add some instructions about this to the installation instructions. But another thing we can do, for people who don't read instructions, is check for the presence of the CSS files and tell people what to do if they're missing. This can go in the pre-install & pre-upgrade sanity check.

[Mahara Bot (dev-mahara)]

Patch for "master" branch: https://reviews.mahara.org/5320

[Mahara Bot (dev-mahara)]

Reviewed: https://reviews.mahara.org/5320
Committed: https://git.nzoss.org.nz/mahara/mahara/commit/9a276988547eb8f7ea5f1f5730dcae663860725b
Submitter: Robert Lyon (<email address hidden>)
Branch: master

commit 9a276988547eb8f7ea5f1f5730dcae663860725b
Author: Aaron Wells <email address hidden>
Date: Mon Sep 21 15:35:51 2015 +1200

Check for compiled CSS in sanity check (Bug 1497821)

Change-Id: I5c147bf0ab19e02718666d16ee52f58a74e926b7
behatnotneeded: Covered by existing tests