better coloring

now ikhal events are colored, too. You can set color to any of urwid's
standard 16 foreground colors, see here:
http://excess.org/urwid/docs/manual/displayattributes.html#standard-foreground

in khal these colors are dependent on your console color settings, in
ikhal it depends on your terminal how these colors are displayed (urwid
tries to reset the colors to the default rgb values).
added simple http(s) (non CalDAV) ics file sync

have a look at the sample config file