Detect and use available font

[pawlakm]

"When FOP does not have a specific font at its disposal (because it's not installed in the operating system or set up in FOP's configuration), the font is replaced with "any". "any" is internally mapped to the Base-14 font "Times" (see above)."

As a result, as Verdana is missing on around 43% of linux installations, batik is unable to set the font family correctly.

Fix to implement:

• detect available fonts
• select font (preference order "Verdana, "Bitstream Vera Sans", "DejaVu Sans", Tahoma, Geneva, Arial, Sans-serif)

Refused fix:

• embed font in plugin

See:

• http://dry.sailingissues.com/linux-equivalents-verdana-arial.html
• https://xmlgraphics.apache.org/fop/2.1/fonts.html

[pawlakm]

first step fix, to be improved using xslt to set the font family correctly.