FORK first (before we destroy things)

Changes:

(1) remove hardcoded pixmap code, replace with hashtable lookups
(2) add pixmap cache (hashtable -> pixmap)
(3) add UI creation file / code
(4) add widget cache (hashtable -> pixmap)

main {
//create image cache
//populate image cache (hardcoded)
//populate image cache (mime-types, scanned from /usr/lib/mime)
//create widget cache
//generate interface elements on-demand

//init stuff (CWD, etc)

//gtk-main
}
