fromHTML assumes jQuery is available #224

- Updated documentation (removed jQuery)
- Removed some unnecessary extra spaces before line endings
- written optimized function in Vanilla JS to retrieve element's
computed style
- frame created using Vanilla JS standard DOM functions
Merge pull request #228 from bolste/master

fromHTML assumes jQuery is available, fix #224
Merge pull request #231 from brettz9/patch-1

Allow for other units
Merge branch 'master' of https://github.com/MrRio/jsPDF.git into patch-1-and-jslint