dvisvgm: create a new PKGBUILD for this

dvisvgm is included in texlive-bin, but that is at version 1.2.2,
while the latest version available from sourceforge is 1.7.

This package uses the autotools configure --program-prefix option to
give the built executable a non-conflicting name. (jb-dvisvgm)
xwit: import from aur