Make QueueOptimizer easier to read.

QueueOptimizer is really hard to read. Enough so that it's blocking my
efforts to streamline the representation used for operator lists.

This patch improves its readability in the following ways.

- More descriptive variable names make the sequence checking much clearer,
  as do additional comments.

- The addState() functions now return the index of the first op past the
  sequence, instead of setting context.currentOperation to the last op of
  the sequence.

- The loop in optimize() is clearer.

- The array modification in the fourth addState() function is much clearer
  -- we're just removing trios of ops.

- All four |addState| functions are now more consistent with each other.

I used some debug printfs to find documents where these optimizations are
used and then checked that the number of optimized ops was the same before
and after my changes.
Minimize memory usage of font-related arrays.

This patch replaces some vanilla arrays with typed arrays, and avoids
some array copying.

It reduces the peak RSS when viewing
http://www.dynacw.co.jp/Portals/3/fontsamplepdf/sample_4942546800828.pdf
from ~940 MiB to ~750 MiB, and reduces its load time from 83 to 76 ms.
Optimize common cases in hexToStr().

This avoids the creation of over two million array objects when viewing
http://www.dynacw.co.jp/Portals/3/fontsamplepdf/sample_4942546800828.pdf,
and reduces load time from 76 to 73 ms.
Converting PDFFindBar and PDFFindController to classes
Re-factor heuristics to recognize unknown glyphs for |toUnicode|
Adjust the heuristics to recognize more cases of unknown glyphs for |toUnicode| (issue 5070)
Compiles some of the FunctionType 4
Optimizes functions to not create arrays
Properly set this.eof in CCITTFaxStream
Merge pull request #5136 from timvandermeij/ccitt-lines

Properly set this.eof in CCITTFaxStream
Merge pull request #5134 from yurydelendik/fun4

Improves speed of the functions
Merge pull request #5008 from nnethercote/better-QueueOpt

Make QueueOptimizer easier to read.
Merge pull request #5095 from Snuffleupagus/issue-5070

Adjust the heuristics to recognize more cases of unknown glyphs for |toUnicode| (issue 5070)
Merge pull request #5007 from timvandermeij/pdfview-tlb

Converting PDFFindBar and PDFFindController to classes
Merge pull request #5071 from nnethercote/font-savings

Optimize a font-heavy document