Simplified source map configuration

sourceMap is now a Boolean that determines whether or not to generate
the map. sourceMapName can be used to customize the name and location.
Merge branch 'master' into updateSourceMap

Conflicts:
	Gruntfile.js
	README.md
	docs/uglify-options.md
	tasks/lib/uglify.js
	tasks/uglify.js
	test/uglify_test.js
Fixes merge conflicts with PR
Merge branch 'updateSourceMap'