travis: Switch from raring to saucy

raring has been removed from the mirrors and was no longer supported
Merge pull request #871 from rleigh-dundee/travis-saucy

travis: Switch from raring to saucy
Move jvm settings to adv. configuration (See #12311)

Now that the default memory configuration need not
be modified by default, it's less critical that the
info be embedded in the main installation page. Also,
this text will need to grow substantially in order to
make the usage clear, and repeating that between unix
and windows seems error prone.

Conflicts:
	omero/sysadmins/server-advanced-configuration.txt
Formatting fixes & grammar improvements
Fix troubleshooting
Clarify 'may want to tune' section
First draft of updated docs
Add :file: markup for indexer, etc
Fix ending periods
Improve psutil/jmx paragraph
Remove use of 'percentage'
Point server-upgrade at jvm_memory_settings
Implement feedback from PR
Remove adaptive strategy
Clarify 'append'
Other wording suggestions
Remove :file: for server names
Unify unix/windows mem blurbs
Fix 'use use' typo