Generate PDF using XeLaTeX
travis: Install xetex and gyre
conf.py: LaTeX font size is 10pt
Update Homebrew installation page to expose Ice 3.4 as the default version

- Describe Ice 3.4 as the default version (e.e. as installed using ``brew in
- Explicit alternate ways to build OMERO with Ice 3.3
- Fix environment variable to reflect the default choice
- Remove deprecated comment in the Ice 3.3 troubleshooting section
Split out main doc sections with bullets

We were already listing them as bullets, but then we also redundantly
linked to them in the introductory paragraph above as well.

Bulleted lists are often much easier to read and digest
(http://www.contentious.com/2004/09/17/bulleted-lists/), so let's just
stick to a single list with the description inline per bullet point.
merge dev_4_4 -D org -I include -E exclude: PR 261 (Generate PDF using XeLaTeX)
merge dev_4_4 -D org -I include -E exclude: PR 368 (Cpp: Correct content and markup)
merge dev_4_4 -D org -I include -E exclude: PR 451 (Update Homebrew installation page to expose Ice 3.4 as the default version)
merge dev_4_4 -D org -I include -E exclude: PR 452 (Split out main doc sections with bullets)