An entry like Categories= creates a desktop file with category set to an empty string
Parsing command line options gives back an option structure
Recognizes command-line option "--iconize"

mjwm would search for proper icon file when iconize is specified [To Be Implemented]
Don't duplicate png extension for an icon file name
Moves services into their own directory
Moves services into their own namespace
Don't duplicate extension if file extension is .png, .svg or .xpm

Fixes #4