Use rects in config to figure out SN and EPIC.

Basically, snBox and epicBox are specified in
the config.  These are based on fractions of
the text rectangle -- likely to work across a
whole lot of lists.  If not, it would be possible
to tweak on an individual or global basis.

This is a far better method than what I had
previously.
Improved segmentation using colons in the text.

I have seen colons in all PDFs. Segmenting based
on them is the new idea.  Delimiter boxes are created,
text boxes within them are extracted, followed by
text conversion & text extraction.

Some extra debug output is produced in the SVG file
to help debug the colon based segmentation.
Added extractTextInOrder. This will come handy next.
Merge glyphs at the time of text extraction.

Fixes shamshudd-in cases, when the glyphs, including
a matra are rendered separately as a string.
Get rid of the separator. This was spoiling the unicode converter.
Simplify code in the text combination logic.
Ignore errors in phase 1, but not in phase 2.