Change unknown extension of PHP sample file
Try shebang detection if the extension is unknown
Refactoring of Language.detect
Merge conflicts from master fixed
Language detection test for non-sample files
Merge branch 'master' into 1233-local

Conflicts:
	lib/linguist/language.rb
	lib/linguist/samples.json
Moving to fixtures
Removing pry runtime dependency
Merge branch 'master' into 1233-local

Conflicts:
	lib/linguist/language.rb
	lib/linguist/languages.yml
	lib/linguist/samples.json
Merge branch 'master' into 1233-local

Conflicts:
	lib/linguist/language.rb
Reworking most heuristics to only return one match
Removing unused array of candidate languages.
Removing inconsistency of `find_by_heuristics` (was sometimes returning nil and sometimes returning and empty array)
Use heuristics earlier to inform the rest of the classification process
Moving comments
Bail earlier if the file is empty.

This will change behavior for empty files with unique extensions, returning nil instead of the language.
Remove more empty samples
remove reference to empty.js
Tests for BlobHelper#empty?
Fix the tm_scope for Less

The source.css.less grammar actually understands Less syntax.