* Move all convert from internal to user units functions into separate file.
* Remove internal units parameter from all moved conversion functions.
* Revise all source code that calls the moved conversion functions.
* Compile these conversion routines separately for the appropriate pcb or
schematic internal units.
* Move internal units specific status bar update code into the appropriate
application for updating the status bar.
* Move millimeter user units rounding function to common.cpp.
Eeschema: Viewlib is now accessible from Libedit (to browse libs or load a component to edit)
Libedit: uses now the same dialog as the schematic editor to load a component
Some code cleaning.