Validator File MimeType (IsImage & IsCompressed)

## Overview
The validators for items that extend MimeType take several options; the design of which causes some potential issues.  This design is still left intact but should be looked at for future versions.

I came over a bug where the default mimetypes were not set when using input filters.  When you utilize one of these as an input filter and pass in custom messages or set any other option the default mimetype options will not be set due to a check of empty in the constructor.  Additionally the parent constructor does a lot of magic to determine if there is indeed a mimetype that can be applied.

The change now allows the parent constructor to set any mimetypes if it can find any and then check to see if any mimetypes have been set; if not it will set the default mimetypes.