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.
prevent php warning, substr_count() length arg should be greater than 0
Update README.md

Information about WordPress integration: JBST WordPress theme
Include WordPress plugin in README.md
Merge pull request #61 from bassjobsen/patch-1

Update README.md
Merge pull request #62 from zghosts/master

fix commandline compiler
firstSelector defaults to true, combinator defaults to string. Fixes #63
Merge remote-tracking branch 'origin/master'
Merge pull request #64 from aristath/master

Include WordPress plugin in README.md
Add Setting Variables section

fixes #66
Parser caching using options array
specify 'source code' for drupal
add Less_Parser->Reset($options) for #12
Merge remote-tracking branch 'origin/master'
possible fix for #72 and change for expected arguments for parseFile()
added package & subpackage docblocs
added package & subpackage docblocs
remove unused code
add bootstrap 3.1 to test fixtures
remove unused code, more accurate check for css extension