Added mutate event for attribute removal

There are many use cases for 
performing a clean up when properties are removed
from a stapes module. A mutate event exposes the 
old value so it can be used in the clean up process.
Updated URL in README to new github.io domain for GitHub Pages

https://github.com/blog/1452-new-github-pages-domain-github-io
Merge pull request #42 from GMFlash/patch-1

Updated URL in README to new github.io domain for GitHub Pages
Adding 'pick' like functionality to get() (issue #38)
Merge pull request #35 from wellcaffeinated/patch-3

Added mutate event for attribute removal
added something to the changelog, added a pre tag to 0.8.1
optimized the bounce example a little bit
Merge branch 'master' of github.com:hay/stapes
.
added tests for class creation, fixed some bugs in the docs
changed the taglien
Added leading and trailing semicolon

Added leading and trailing semicolon to prevent breakage in concat (leading is for concatenated file in front of Stapes that might be missing a semicolon.).
Added semicolon

Added semicolon to prevent breakage in concatenated files.
Merge pull request #47 from RWOverdijk/patch-2

Added semicolon
Merge pull request #46 from RWOverdijk/patch-1

Added leading and trailing semicolon
changed tagline in README.MD
adding first setup for new website
adding scrollspy
moved some docs around
moved even more stuff around