t2k should setup gridfitting environment only when needed

Start of minimal FX app generated by Netbeans (with signle text String) causes 200 calls to TrueTypeFont.readBlock() on Windows.

Further analysis shows that most of the blocks are read from
  arial.ttf
  wingding.ttf
  symbol.ttf
  LucidaSansRegular.ttf

One of the major contributoros seems to be initialization of TextLayout that requests font metrics for the logical font.
Apparently this casues setupT2K() to be called that always setups grid fitting environment. As part of
setup of grid fitting environemnt global hints are computed and this cause some glyphs to be read from
different parts of the font file.

This initialization is done once but if font is not actually used to draw any glyphs (and this is the case
for some of physical fonts composing logical font) then this is uneeded work.