Fix #952: Improved documentation of validation

Added note for translation of labels in validation rules.
Fix #679 Assets::js() returns nothing if a string is passed as first argument
Update changelog

Eventually I'll remember to do this at the same time as the changes...
Fix issue number for #954
Forces all driver files to be ucfirst, which the manual implies is the required version anyway. Hopefully fixes #946
Updating changelog
Merge branch 'develop' of github.com:ci-bonfire/Bonfire into develop