Issue #2003628 by corey.aufang: lessjs is now run through a class.
Issue #2221237 by corey.aufang: Cleaned up integration and library
lookup.
Issue #988552  by corey.aufang: Import paths are now working with all
engines.
Issue #2203549 by corey.aufang: Source maps are now working correctly
with lessjs and oyejorge/less.php (requires latest dev of
oyejorge/less.php).
by corey.aufang: Cleaned up hook_libraries_info().