* Allow to select units in components that have more than one right in the
component chooser dialog.
* Keep chosen unit in history.
* Show preview of current component unit as thumbnail image next to the
description box.
* Fixes lp:1280567
*) add hotkey for setting the grid origin as 'S', in board editor, module editor.
*) re-position the function interface for cursor movement from BASE_SCREEN into
class EDA_DRAW_FRAME. This is a prelude to getting rid of BASE_SCREEN or
splitting it up.
* 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.
Henner Zeller
Dick Hollenbeck
jean-pierre charras
Wayne Stambaugh