This pull request solves issue #674, see it for details.
Adding QMake (Make-like) language.

Mostly because the file extension conflicts with that of Prolog.
Support of the .pro file extension for Prolog.
Merge branch 'master' of https://github.com/github/linguist into pro
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.
Improved the C++ heuristic for detecting based on included headers
Improved the Obj-C heuristic with a Regex matching multiple unique keywords

Also improved the C++ heuristic by checking for class without an @ on the front.
Added the end statements for the two new if statmeents

Did not know ends were required on one-liner ifs. Fixed.
Fixed the failing patten for detecting C++-only headers
More regex goodness to improve the detection of C++ vs C
Found out that nothing was ever getting returned from the heuristic function "find_by_heuristics", and that headers matching C, Obj-C and C++ were never getting checked heuristically
Fixed the C++ class matching regex that was breaking the test for C/jni_layer.h
Found my new heuristic was still not being used because heuristics had been switched off
Added two new heuristics tests for the new C/C++/Obj-C heuristics
Merge branch 'master' of github.com:DX-MON/linguist
Removed the matches variable from find_by_heuristics without re-breaking anything
Updated the samples database file as recommended
Idris is upstream in Pygments now: https://bitbucket.org/birkenfeld/pygments-main/pull-request/210
Add support for Cool

This change includes a brief (non-sensical) sample program I wrote to
illustrate many of Cool's language constructs, as well as a simple rule
to distinguish Cool files from Common Lisp or OpenCL (it has a line that
starts with the word 'class'). Further, it includes a second example
program adapted from an example contained in the Cool distribution
(list.cl), which contains a few further language constructs and captures
the style of a Cool program.
update