Fix Icon Lookups to match hicolor reference theme structure

First came across this problem when 90% of my applications where triggering this error on pop-up notifications
naughty: Couldn't load image 'bad': /usr/share/awesome/lib/gears/surface.lua:37: Failed to open file 'bad': No such file or directory

Seems that  awful.util.geticonpath couldn't find images when referenced only by iconname
In order to match more XDG style reference theme icons (hicolor, HiContrast, Gnome, Oxygen, etc)
these all take the structure SizexSize/IconType/IconName.Extension
Where size is anywhere from 8x8 to 128x128 and
Icon Type is a list of types (See code)
Extension is 99% of the time png, sometimes svg

In the long term some GIO / Glib stuff should be used to properly parse the theme index.theme file and find the icon instead of this, but .. this is just a patch


Also people should really do

naughty.config.icon_dirs = { "~/.icons/" , "/usr/share/icons/hicolor/", "/usr/share/pixmaps/", "/usr/share/icons/" .. beautiful.icon_theme  .."/"}

somewhere in maybe rc.lua??