Fixed inconsistent indentation

Converted tabs to spaces
Added options.linebreak

If true (default), adds line break between banner and content.
Otherwise don't add line break.
Removed unused test setUp and tearDown and removed setUp of next test from bannerBottom test.

Removed dependency on test/fixtures/ being reset at end of test.

Test fixtures are now prepared by node-contrib-copy task (copies test/fixture/ to test/tmp/).
Added test for options.linebreak
Updated Readme with info about options.linebreak
fix: use grunt.util.linefeed instead of hard-coding '\n'

using grunt.log replaced with grunt.verbose

Conflicts:
	tasks/usebanner.js