Fix error when matching languages against heuristics: if no language, no heuristic rule should be used
Unit test for fix #1809 on heuristics
Fix for fixture tests: fixture files were not tested at all
Use namespace.js for the heuristic test with no match
Remove .module extension for PHP
Merge pull request #1809 from pchaigno/fix-matches-heuristics

Fix error when matching languages against heuristics
Bumping linguist version
Merge pull request #1812 from github/cut-release-v4.2.1

Bumping linguist version