[Denemo-devel] added excerpt and export export to png support

[Jeremiah Benham]

I just committed a change to git to allow users to export to png or
create music excerpts. At the moment it is not completely finished. In
the future it should have a dialog or something to ask you which
measures to create an excerpt from. This way the user wants to create a
one or two measure exercise that can be included in an OpenOffice.org
document or something. Note that it does not print the entire page. This
is the intended result. Later I also plan on adding .eps for inclusion
in LaTeX documents. 

This way a user can use denemo in combination with OpenOffice.org or
LaTeX to create books that have musical examples in it. 

Jeremiah