Expand (or add) more validating steps

[ypujante]

Right now there is a validate / validate45 command/target and it would be great to either expand, or add new targets for other kinds of validation/utilities. For example, @DavidAntliff has some useful scripts to deal with missing/unused texts (unclear if this is part of the validate command or just another command at this stage). Hopefully other developers have written other kinds of helpers that would be great to integrate in the framework