Various fixes/improvements:

- Remove tampering with include path.
- Remove tampering with default timezone.
- Add debug for exceptions and last Soap request.
- Reformat payment form template to be consistent with Magento default
  template.
- Fix string parse error in regexes (\d in double-quoted string).
- Add previous exception to extended exception classes where
  appropriate.
Prefer SOAP extension over PEAR library. noref
Various cleanup and security improvements:

- Validate customer owns token before delete or retrieve data.
- Fix error handling/reporting (session messages).
- Add expiration date to saved cards select menu.
- Refactor javascript in form to make use of Prototype, reduce global
  namespace footprint, use cross-browser compatible event handlers.
- Remove incorrect/unnecessary window.onload assignment.
- Fix setLoadWaiting usage in some cases.
- Improve javascript error handling.
- Remove duplicated code from Payment#save method (store reference to
  old function).
- Replace JSON.parse with String#evalJSON since JSON.parse is not
  present in older browsers.
- Remove reference to HPS object not defined in global scope.
- Do not log if console.log is not defined.
Fix stored cards template. noref
Retrieve token data by storedcard_id instaed of token value. noref
Fix javascript bugs. noref
Fix CC exp month with saved card. noref
Fix 'Notice: Undefined property: stdClass::$Header' error
Fix regression on unused method of HpsException.
Fix ref to undefined class.
Merge pull request #20 from colinmollenhour/rebase

Various improvements and fixes