upgraded lesscss compile to 1.3.1 and added initial support for lesscss compress option
Merge remote-tracking branch 'origin/master'

Conflicts:
	grails-app/conf/BuildConfig.groovy
	grails-app/resourceMappers/LesscssResourceMapper.groovy
	test/unit/LesscssResourceMapperTests.groovy
excluded css and js, added image needed for rests to pass