Gherkin support

Hacked into shape from this
https://github.com/cucumber/gherkin-syntax-highlighters
Ignore RubyMine cruft
Capture do, end, /^step def text$/
Gherkin test (I think)
Gherkin done
Step Defs

I think this is a bit simplistic, but it works
Add support for interactive ruby sessions (irb)
Reintegrate irb definition into the ruby one
Add built_in functions for R language

Add some keywords from (highlight)[http://cran.r-project.org/web/packages/highlight/index.html] R package. It's the most complete list.
Merge pull request #432 from unikum/patch-1

Add built_in functions for R language
Added Monkey language support
Fixed header detection of function and method
Improved relevance for Monkey language
Improved variable type detection for Monkey language
Revert "Add built_in functions for R language"

This reverts commit 3d69f0ad8d8b7452985a54f758e4b23b23223920.
Merge branch 'monkey-language' of github.com:devolonter/highlight.js into monkey
Resetting most custom relevances in monkey.js.
Resetting even more custom relevances in monkey.js keywords.
Gherkin definition
Merge branch 'feature-gherkin' of github.com:matteofigus/highlight.js into gherkin

Conflicts:
	.gitignore