Add Chapel parallel programming language.

Includes several example programs from source distribution.
Include Chapel in some of the language tests.
Merge remote-tracking branch 'github/master' into chapel-lang

Conflicts:
	lib/linguist/samples.json
Merge remote-tracking branch 'github/master' into chapel-lang

Conflicts:
	lib/linguist/samples.json
Merge branch 'master' of github.com:github/linguist into chapel-lang

Conflicts:
	lib/linguist/samples.json
Merge branch 'master' into 1348-local

Conflicts:
	lib/linguist/samples.json
Merge branch 'master' into 1348-local

Conflicts:
	lib/linguist/samples.json
Merge pull request #1458 from github/1348-local

1348 local