Move OMERO documentation to omero/ subfolder
Fix compilation by pointing at the themes/ directory
Remove formats from excluded patterns in OMERO documentation
Move shared configuration settings to common configuration file

- Common configuration moved to common/conf.py
- Move themes to common/
Add central Makefile to build OMERO & Formats documentations at once

Also allows Travis script command to remain unchanged
Fixing broken links & reformating git.o to github
Fixing redirected links
Install textlive and add latexpdf to the command of the Travis build
merge dev_4_4 -D org -I include -E exclude: PR 281 (Review Matlab documentation (see #10389))
merge dev_4_4 -D org -I include -E exclude: PR 310 (Do not expose OMERO_HOME in the doc (see #10603))
merge dev_4_4 -D org -I include -E exclude: PR 315 (Doc reorganization)
merge dev_4_4 -D org -I include -E exclude: PR 316 (Fixing Formats links)
merge dev_4_4 -D org -I include -E exclude: PR 317 (Add latexpdf to the Travis build)