[PATCH] TTFReader: Output bounding box information for glyphs

As I mentioned in another email, I am trying to constrain FOP to use only
local fonts (i.e. ones described in fop.cfg). For SVGs, I have a workaround:

• Generate fonts in SVG format using ttf2svg utility from Batik;
• Use an XSL stylesheet to embed all the fonts used by an SVG image into the
  image itself;
• Use such "preprocessed" SVG image as the input to FOP.

This does not work well with JEuclid, though. When JEuclid generates SVG from
MathML, it performs font rendering - that is, replaces characters by actual
paths. And again, it uses system fonts, not the fonts available in FOP - even
if running as FOP plugin.

To work around this issue for MathML, I am currently switching from JEuclid to
pMML2SVG (http://pmml2svg.sourceforge.net). It generates SVGs with text
characters, not paths. But in order to do so, it needs font metrics.
Unfortunately, font metrics produced by stock FOP TTFReader are not sufficient

• this stylesheet also needs bounding box for each glyph. To obtain these,
  pMML2SVG currently packages an augmented TTFReader Java sources which are to
  be compiled and used in lieu of the stock one.

Given that the patch is very small and as far as I can tell, compatible with
current users of font metrics (it just adds 4 attributes to glyph
description), is it possible to integrate this support into stock FOP?

Patch from pMML2SVG, slightly modified to apply to FOP 1.1 sources, attached.