Merge pull request #770 from emmanuel-keller/master

Fix #737
Merge pull request #773 from emmanuel-keller/master

Implements #717
Merge pull request #784 from emmanuel-keller/master

PDFViewer based on GhostScript
Update documentation: add link to last version of PHP client
Update documentation: update summary
Merge pull request #785 from AlexandreToyer/master

Update documentation: add link to new PHP client
Merge pull request #788 from emmanuel-keller/master

Fix NullPointerException at WriterLocal.java:306
Update README.md

Tiny typo.
Update README.md

Tiny typo.
Update inject.md

Small language issues.
Update SUMMARY.md

Tiny typo.
Update README.md

Tiny language issue.
Update SUMMARY.md

Tiny language issue.
Merge pull request #793 from emmanuel-keller/master

Fix NullPointerException at StringUtils.java:105
Merge pull request #795 from emmanuel-keller/master

Fix NullPointerException at
Merge pull request #802 from emmanuel-keller/master

PDFParser: optional usage of Ghostscript
Merge pull request #806 from emmanuel-keller/master

Implements #803
Merge pull request #809 from emmanuel-keller/master

Implements #719
Merge pull request #810 from emmanuel-keller/master

Update change log
Merge pull request #813 from emmanuel-keller/master

Prepare RPM package