Make SQL a programming language

Because it is (see https://github.com/waveform80/db2utils which hilariously claims to be 79% written in C!)
Amend tests to ensure SQL *is* searchable
Add support for Processing's new Python Mode sketches.
Delete primary_extension from language data

The language attribute is still maintained as the first extension found.

This allows Mercury to be properly detected by Linguist, as per #748.
Missing type added to Cuda
Merge branch 'master' into 985

Conflicts:
	lib/linguist/languages.yml
Note on extensions
Formatting
Formatting
Merge pull request #1167 from github/the-end-of-primary-extension

RIP `primary_extension`. / cc @nox @tnm @bkeepers @rick
Merge pull request #1166 from pchaigno/cuda-type

Programming type added to Cuda
Merge branch 'master' into 950

Conflicts:
	lib/linguist/languages.yml
Merge pull request #1168 from github/950-update

950 update
Add Python processing examples.
Merge pull request #1136 from jdf/master

Add support for Processing's new Python Mode sketches.
Samples update
Add FORTRAN samples.
Add Forth extensions .f and .for; add heuristics for Forth and FORTRAN.
Update samples.json.