More reliable bower install postinstall.

This makes the bower i work on Mac, Win.
Add mismatchTolerance, update PhantomCSS.
Add copyright notice, update README.
v0.3.0

* Added `mismatchTolerance` tolerance (`mismatchTolerance: 0.0.5` is default) (thx [fidgety](https://github.com/chrisgladd/grunt-phantomcss/pull/17))
* Use PhantomCSS v0.7.1
* Update dependencies
* Remove grunt as peerDependency causing multiple issues with peerPackages
* Fix post-script `bower install`
Small changes to code style

Mostly re-indentation or similar.
Update visual regression test screenshots.
Update dependencies.
Add editorconfig, update Grunt task.
v0.3.1

* Add time-grunt to measure build times
* Add jit-grunt to load tasks only when needed (+ improve performance)
* Change log level to notice in Gruntfile
* Document correct CasperJS log levels and pass them as arguments / option
* Added .editorconfig
Get back to notice log level
Add `waitTimeout` as option
Add mismatchTolerance as an option in documented options
Merge branch 'master' of github.com:anselmh/grunt-phantomcss
update phantomjs version