Add misser lexer entry for nesC to languages.yml

The nesC entry in the languages.yml file was missing a lexer entry
and thus wasn't getting picked up. This adds the required lexer line.
Add R package ignores to vendor.yml

Ignore vignette and external data directories which contain no R source code
Use the :ruby_encoding value from charlock 0.7.2
test ruby_encoding
forgot to add the test fixture
Merge pull request #1253 from github/newer-charlock

Use the :ruby_encoding value from charlock 0.7.2
bump version for v2.11.4 release
Merge pull request #1254 from github/cut-release-v2.11.4

v2.11.4 release
Merge branch 'master' into 814

Conflicts:
	lib/linguist/languages.yml
Change R package ignores to absolute paths
nesC
Merge pull request #1255 from github/680-update

680 update
Merge branch 'master' into 1042

Conflicts:
	lib/linguist/vendor.yml
Merge commit 'refs/pull/1042/head' of github.com:github/linguist into 1042

Conflicts:
	lib/linguist/vendor.yml
Merge pull request #1256 from github/1042-update

1042 update
Add support for the Varnish VCL edge scripting language
Merge pull request #1257 from simonwistow/master

Add support for the Varnish VCL edge scripting language
Add a multitude of Forth file extensions.
Yes, these are all in use.
Add Groff sample.
Update samples.json.