Make the code strict mode-compliant: declare variables before using them in "if" condition

Also, some trailing whitespaces removed by my editor.
"required" rule support for radio inputs

Multiple radio inputs share the same name in the form, but vary in values; therefore form["foo"]
is not an HTMLInputElement, but rather an array of HTMLInputElement-s.
added is_file_type validator
added short explanation of is_file_type hook
added ignore for is_file_type hook if field type is not file
Added "rule" to error-object
Clarified that validate.js is licenced under the MIT licence
Added Credit Card Validation (using luhn check method from https://gist.github.com/4075533
Merge pull request #47 from TERMINALFOUR/credit-card-validation

Added Credit Card Validation
Merge pull request #45 from TERMINALFOUR/licence-change

Clarified that validate.js is licenced under the MIT licence
Fixed a typo in the license.
Merged in pull request #44 from jhnns.
Updated the email regex to the html5 standard.
Merged in pull request #34 from tricinel.
Merged in pull request #25 from ikr.
Updated version number to 1.2
Merge branch 'master' of github.com:rickharrison/validate.js

Conflicts:
	validate.js