abiword: build the mathview plugin
Without the gtkmathview dependency the abiword mathview plugin is not
built,which prevent the edition of the math formulas(mathml or latex
formulation)
I also had issues displaying the formulas on my eeepc 701
(machine support will be commited soon) without the plugin:
*The 3 top formulas of my document had a black rectangle on a part of
them
*the part after the black rectangle was truncated and mixed
Installing the plugin fixed both issues,but I noticied an issue
with the latex notation where a \cdot was transformed in a C with
a vertical bar in it(like the $)