Update to Chemtool 1.6.12.

Changes since previous package:

Chemtool-1.6.12 (June 7, 2009)

This release contains another round of fixes for label positioning
and clipping of bonds around labels. The pen color button has been
replaced by a drop-down menu, and a "white" pen for drawing on
colored backgrounds has been added. Chemtool now automatically
resizes its main window on small (netbook) screens, and it can also
be used in an non-interactive mode to create postscript (etc.) output
from previously created chemtool structure files. The Polish
translation has been updated, and a new Bulgarian translation
has been added.

Chemtool-1.6.11 (August 26, 2007)

This release contains numerous fixes for label positioning and
sub/superscript kerning. Bond length and zoom factor are now
stored with the drawing, bond clipping of multiple bonds was
improved and new special key sequences for circled plus and
minus symbols were added. The configuration dialog now lists
gtklp among the supported print commands. Source layout and
build system were reorganized to make addition of translations
easier, and a Portuguese localization file was added.

Chemtool-1.6.10 (April 8th, 2007)

This release adds PNG export, round brackets, text output in
east-european locales and some new templates. Several bugs
related to special character handling in GTK2, screen display
of labels and exporting to EPS and SVG have been fixed. The
configuration dialog has been redone and now includes support
for kprinter, and the labeling shortcuts no longer interfere
with GTK's menu accelerators.

(asau)