Adding UltiSnips snippets, updating Readme

UltiSnips snippets are taken from UltiSnips repo.
Putting them nearby the engine seems to be the wrong thing to do.
One reason is that there are two forks now.
merge changes from pull/179
fix FSF address

Per http://www.gnu.org/licenses/gpl-howto.html.
add reqr to expand to require_relative
Merge pull request #180 from mwcz/master

Added a semicolon to the sdf (self-defining function) javascript snippet
add configurable property snippets