Add adobe CMaps.
Use built in CMaps and unify the glyph mapping.
Fix symbol fonts with no file.
Remove isFixedPitch check for now.
Use default encoding for standard fonts without a file.
Add note about adobe license.
Fixes corrupted by Aspose fonts.
Estimate the size of decoded streams in advance.

When decoding a stream, the decode buffer is often grown multiple times, its
byte size increasing like so: 512, 1024, 2048, etc. This patch estimates the
minimum size in advance (using the length of the encoded stream), often
allowing the smaller sizes to be skipped. It also renames numerous |length|
variables as |maybeLength| to make it clear that they can be |null|.

I measured this change on eight documents. This change reduces the cumulative
size of decode buffer allocations by 0--32%, with 10--20% being typical. This
reduces peak RSS by 10 or 20 MiB for several of them.
Merge pull request #4259 from brendandahl/built-in-cmaps-squash

Adds built in CMaps and unifies the glyph mapping.
Prevent circular reference when checking for blend modes (issue 4370)
Merge branch 'master' of github.com:mozilla/pdf.js into issue-4370
Merge pull request #4437 from yurydelendik/issue4398

Fixes corrupted by Aspose fonts
Merge pull request #4444 from nnethercote/min-length

Estimate the size of decoded streams in advance.