EWMH Window Types

[Viktor Griph]

The way fvwm handles the _NET_WM_WINDOW_TYPE hint is very 
non-configurable currently. You can't even set other style options on the 
windows yourself.

There are several ways to improve this. In short term a style 
EWMHIgnoreWindowType would allow for users to set their own style on 
windows having a specific windowtype without being foced to also have the 
default options of that window type. While this is an easy-to-make 
solution, I think there is room for more improvment. It would be good with 
configurable styles on a window type level, also for the window types 
currently ignored by fvwm. A command "EWMHWindowTypeStyle" could be added, 
and when the Style command is changed according to the 3.0 todo "Type" could 
be made a option to match on.

I already got an implementation of the EWMHIgnoreWindowType which is ready 
for commit if agreed that such a style woud be useful (there might be 
other better solutions to the problem). I'd like to take a look at the 
implementation of an EWMHWindowTypeStyle command once I get a little more 
spare time.

/Viktor