[Urwid] Patches to the library: more attributes and colors

[Ian Ward]

Derek Peschel wrote:
> 	- Add my terminal name "osxterm" to the list of terminals that
> 	  can display 16 fg/16 bg colors.  In a curses-centric world
> 	  where everyone had correct terminfo files, urwid would detect
> 	  the number of colors the terminal supports and whether bold is
> 	  related.  There are conventions for both, even if they're
> 	  not perfect.  These patches are not that good yet.  And how
> 	  does the "curses-centric world" idea fit in with everyone's
> 	  future plans for urwid?

This "osxterm" setting wouldn't be useful for people that haven't 
installed your terminfo file, right?  Also, the change to curses will 
make Urwid crash on terminals that curses thinks only have 8 colours.

Regarding the background colours, I did some testing with different 
terminal emulators on my system and I found that support for 16 
background colours is quite limited.  If I do add these colours I'm 
worried that applications that use these colours will look really bad on 
many user's terminals.

Regarding the other attributes (bold, underline, etc) I have been 
considering allowing them to be combined with regular foreground 
attributes because they seem to work properly in most of the terminals I 
have tested.

Ian