Fix a problem about Japanese PDFs without embedded fonts
Added a test PDF having Identity-H encoding without embedded font
Support corrupted pdfs that are encrypted but lack 'ID' in trailer
Merge pull request #2562 from vyv03354/master

Fix a problem about Japanese PDFs without embedded fonts
Merge pull request #2547 from mduan/issue2085

Support corrupted pdfs that are encrypted but lack 'ID' in trailer
Handle missing 'FontName' entry in FontDescriptor object
Merge pull request #2566 from mduan/issue2099

Handle missing 'FontName' entry in FontDescriptor object