Fixed bugs 2981754 and 2981759 (PCBnew crash when trying to add a new net name to a pad) Linux specific, and perhaps due to a bug in wxGTK 2.8 (does not happen in 2.9)

* Some bugs fixed
* Starting enhancements in Libedit: menubar and commands to "plot" current component in PNG or SVF file (SVG file not fully working, must be refined)

German translation update. Replaced dialog page settings dialogblock version by the same built with wxFormBuilder

Updated Polish translation from new member of Polish Kicad Team: Paweł Dras <dexx.electronic@gmail.com>
Thanks!

default is Edit pin per pin for components with parts locked and coupling pin for others.

This patch applies on the very last svn  (r2402) and removes all
disfunctionnal python code (including deletion of unused strings)

All: fixing a recent problem when using scroll bars: the full screen was redrawn, that can be very slow in Pcbnew.