fix a compil warning.
CvPcb: fix regressions :
Shows now a void field instead of the dummy footprint name $nonane (whenthere is no footprint selected in netlist).
The active footprint selection changes only if a new component is selected from the component file,
and does not change just when the next component is automatically selected, after a footprint selection.
Speed up delete association and auto associe.
* Grammar and spelling fixes in Eeschema, CvPcb, and Pcbnew path and
library dialog tool tips.
* Translate the French file name subrill.cpp to highlight.cpp.
* Lots of coding style policy fixes.