Python command line scripting

See merge request !129

ACG Matrix3x3T: add getRow() and getCol() convenience getters

See merge request !128

Python support

See merge request !127

Fixed alignment of text in pytthon widget

Reintroduced PythonInterface to identify plugins with python support, List plugins with python support in the python widget

Fix bug in File loader plugin selection.

See merge request !126

Bug example: OVM loads *.volumemesh files, however the previous logic would
also try to use this plugin to load a *.mesh file, because "mesh" is a
suffix of "volumemesh"

This change adopts the same logic exhibited in Core/openFunctions.cc to
require an advertised filetype to have a suffix of "*.ext", not of "ext"
when trying to load a file "foo.ext".