Update getBestReader : do not check if the file exist.
getBestPlugin: sort readers by evaluation

How to sort:
first - highest evaluation
second - lowest number of supported extensions
third - plugin name
getBestPlugin: only one getBestReader function

* all functions accept a filename or an extension
* change the rules:
** if the file doesn't exist, return the plugin based on the extension
** if the file exist, try each plugin
* refactor: add a function getFileExtension
* getBestWriter: bug fix
* more precise error messages
gitignore: ignore TuttleOFX-data
minor code simplification
update sconsProject
getBestPlugin: move source code and install in the python output directory

* getBestPlugin is no more in application/example, but in
libraries/tuttle
* is installed in OUTPUTDIR/python (and no more
OUTPUTDIR/python/example)
* is installed with pyTuttle
* add a scripttest