implement data-uri([mimetype,] url) from less.js 1.4.0
data-uri: add tests and use lessc::findImport to locate the file
use the built-in php magic database instead of the system one
Merge pull request #500 from nyordanov/master

Implement data-uri([mimetype,] url) from less.js 1.4.0
Fixed broken bootcode namespacing.
Accurate source file and line number when throwing undefined mixin or unknown block operation error.
Removed oyejorge’s lessphp.
Merge.
Merge commit 'bcca533a1f785f5e89f5620f9aeba0c2a6abe045'