Update napi.sh

Support for ffmpeg in framerate detection.
Ability to add abbreviation to extension

Ability to add abbreviation to extension - for example language code. Needed for integration with filebot.
Fixes according to dagon666 comments
modifications to test_tool to be more thorough
Subotage updated to return an -1 (255) error code in case of a conversion problem
Merge branch 'master' of git://github.com/emfor/napi into emfor-merge
Updated the authors file and incremented the version counters
Corrections to the abbreviations code
re-working abbreviations
Abbreviations support corrections
Merge branch 'origin/emfor-merge'