Add X resources definition for XTerm and family.

[matttproud]

This commit includes color scheme support for XTerm and related applications. I programmatically generated this from the iTerm 2 theme using a tool I wrote: github.com/matttproud/hodler. I have manually tested this, and it appears to uphold the tenets of your theme as best as XTerm can.

You can load it with …

$ xrdb -load Xresources

… or inlining using the #include directive in your personal .Xresources or .Xdefaults files.