HTML validation fixes.
Merge pull request #1186 from phaidon/html-validation-fix

HTML validation patch.
correct value check in template for category registry
check for value of 'reason' in dependency and return empty string if not set. refs #770 and refs #766 @cmfcmf
Temporary fix for TraceableEventDispatcher refs #1183
fix typo
Merge pull request #1188 from craigh/typofix

fix typo
Revert temporary workaround for Symfony TraceableEventDispatcher

Fixed upstream
Remove external vendor dependency that's now built into PHP 5.3
Move legacy Loader, then we dont need a separate entry in composer for it.
Add note about arguements sent to controller methods.