TkAgg backend issues

JDH... do you have any idea where to put it?

I created a dir in CVS "license" which contains

LICENSE - the matplotlib license

LICENSE_PAINT - not really required anymore since font.cpp is no
  longer used

LICENSE_PIL - you can refer to this in the appropriate tkagg src
files

I also made a committed of couple of minor changes earlier to the
tkagg src that Andrew suggested to me that enable it to build cleanly
on OS X. With the current CVS setup.py and setupext.py, I can build
all the backends on linux, win32 and darwin, which is *a good thing*
:-).

JDH