Refactored PdfObjectString into a struct with bool flag for hex. Fixed any code broken by the change.
Unexported non-essential functions for crypto (not used by model). Can unexport more later or refactor to internal package.
- Added Type1 font parsing.
- Added Standard 14 font parsing.
- Fixed some bugs in cmap code.
- Started re-structuring of font code. Moved common font fields to `fontSkeleton`
Support avg, paeth predictors for decoding. Special error flag for
unsupported error parameters. Support specifying encoder when creating
new image objects (inline,xobject).
As the package was growing large, there is a need to clean up. Testing
to refactor into a core (basic pdf parsing and primitive objects) and a
higher level model package.
