modify docs for supporting multiple versions.
update docs help.txt and online instructions page;
use vars in _config.yml for version, rather than files in fields/* ;
include version in the top-right corner;
show versions ahead of governance in toc; and
make versions.md dependent on where we are running what it shows,
  and a place to list version history, key changes, etc

(backport of 604e6b80db1fa6d7b4af69f01d819f44360b1ebd)
fix change-version to be simpler, more powerful, and more portable (multiline sed)
bump to tomcat v 7.0.34 (since 7.0.32 no longer available)
various files which required additional annotations or manual changes for version updates
don't refer to previous artifacts in 0.4.0 branch documentation
Merge pull request #444 from ahgittin/v/0.4.0-SNAPSHOT

docs support versioning