Add XFiles Xresources & scripts

[morgant]

I really like Lucas de Sena's XFiles, and am switching to using it instead of xwf. In addition to Mac-like themed Xresources for XFiles (I'm using ~/.Xresources.xfiles) and XMenu, I'll also need to provide an xfilesctl script which will provide Mac-like contextual menu options and functionality for XFiles.

[morgant]

Note-to-self: commit a04f4d1 added .mlvwm/.Xdefaults file, .mlvwm/Xresources/ directory for application-specific Xresources files, and documentation in the README.

[morgant]

Another note-to-self: some further research/discussion by me regarding XMenu Xresources which will likely be helpful.

I've also noticed that my xsndiomenu project doesn't actually include the XMenu Xresources that I'm using.