Update less to 1.4.1. It has some minor backwards-incompatible changes, see: http://lesscss.org/
Major overhaul/cleanup:

 * Did away with flattenLessText. Now using the real less
   parser/renderer and inspecting the list of imported files
   when computing the compiless ETag.
 * No longer wrapping the less compilation in a try..catch.
   Apparently they fixed the code in 1.4.x so that it doesn't
   throw in async code.
Release 0.3.0.