This pull request solves issue #674, see it for details.
Basic SAS

Just an entry for SAS with the basic .sas file extension and two
examples.
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.
bundle fix

Lets see if this fixes the failing tests
Adding QMake (Make-like) language.

Mostly because the file extension conflicts with that of Prolog.
Added Propeller Spin language to languages.yml
Add misclassified Prolog samples

These two files are incorrectly classified as Perl.  They should be
classified as Prolog.  There are many distinctive tokens in each file
which clearly differentiate between Perl and Prolog.
included sample and extension .ML extension for Standard ML files
Add R package ignores to vendor.yml

Ignore vignette and external data directories which contain no R source code
Merge branch 'master' into 815

Conflicts:
	lib/linguist/samples.json
Idris is upstream in Pygments now: https://bitbucket.org/birkenfeld/pygments-main/pull-request/210
Add more extensions based on XML
Added sample Spin code objects to samples/Propeller Spin/
Converted spin samples from UTF16LE to UTF8 character encoding.
Changed Propeller Spin primary_extension key to extensions and set value as array
Add samples as requested.
add release instructions to README
improve release instructions
one more tweak
Merge pull request #1172 from github/include-release-instructions-in-readme

add release instructions to README