Allow user to exceed maxlength

Add option to pass in custom attribute to allow user to exceed
maxlength.  Validation is handled by user using 'overmax' class that is
added when maxlength is exceeded.  Code example added to readme file.
Fix readme file to display HTML

Display HTML in readme
Correct jscs errors

Correct jscs errors
Update over maxlength functionality

Update over maxlength functionality and add unit tests.
Correct javascript error

Correct missing semicolon
Fix javascript error

Remove comment
Unit Test

Updated units tests and added 2 more.
Updated unit tests

Updated unit tests
Merge pull request #73 from ashleyglee/master

Allow user to exceed maxlength