call for comments/vote on new functionality and keyword

[thomas bonfort]

hi list.
I've added the possibility to have "halo" type outlines on label text
"à la google maps" for agg :

http://terriscope.fr/ms_tmp/fontoutline.png

as Hobu (kindly;) suggested, I made this user selectable by adding a
new keyword, OUTLINEWIDTH for the LABEL block, and a new member to the
labelObj.
so:
mapfile.h gets a new #define OUTLINEWIDTH
maplexer.l gets a new line for OUTLINEWIDTH
mapserver.h has a new int entry for the labelObj typedef
mapfile.c is modified for the initialisation and parsing of the labelObj

there are no other changes apart from the actual rendering in mapagg.cpp.

OUTLINEWIDTH defaults to 1, and in that case the current outlining
method is used. if OUTLINEWIDTH>1, the softer outline rendering kicks
in.

it's a rather small fix, but as it implies adding a keyword (which by
the way I'd like to see used elsewhere to avoid the SIZE/WIDTH
terminology mixup), I thought I'd ask for your feedback on it.

comments anyone?

cheers,
thomas