Add checkedCompile

For more compatibility with lessphp.
This isn't used by Assetic, but I used it in my own framework. There are probably more people using this, so this makes it easier to move.
Add more compatibility to lessc.inc.php

Enable a working version of setVariables and modify the constructor definition.
Windows compatibility
Improved Windows compatibility
Windows improvement keeps valid uri's

The previous improvement broke the uri's. Now the path is converted to forward slashes and system-normalization is left to php.
Update README.md

change the example built-in mixin
see also: https://github.com/bassjobsen/jamedo-bootstrap-start-theme/issues/108
Merge pull request #78 from bassjobsen/patch-2

Update README.md
correct uri for import directories in less.inc.php. fixes #72
Merge remote-tracking branch 'origin/master'
Merge pull request #77 from storeman/master

Windows compatibility
convert all backslash to slash in normalize path
Convert windows paths in Less_Parser instead of NormalizePath for #77
Adding missing function setVariable

That's what I get for trying to poach things one at a time and edit in the online editor...
Remove compression option

I had this hardcoded in my version, but removed it for compatibility.
Add lessjs-config.js
Merge pull request #73 from fabrizim/master

Add more compatibility to lessc.inc.php
Merge pull request #54 from barryvdh/patch-1

Add checkedCompile
Add tests for #80
Add CheckCacheDir(), allow passing cache_dir as option to Less_Cache methods
move phpunit tests, add sourcemap test