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.

Code cleaning and other minor fixes.

 * Added a dialog to select options: one or 2 files, units (mm or inch), and force INSERT option.
 * code cleaning
 * Modify corresponding  icon in menu to show a footprint, not a schematic component.

Icons for modedit and modview: remove unused or duplicate icons files and rename files. Tweak some icons.

Pcbnew: Added: modview. This footprint viewer frame which has the same purpose as Viewlib in Eeschema.
this viewer is built using the new  FOOTPRINT_VIEWER_FRAME class.

Pcbnew: Fix incorrect behavior of undo/redo command (this issue happens only when a new track is created, and an old redundant track is deleted)
Minor code cleaning

Pcbnew:  First draft to use a new netlist format ( containing the same info as the intermediate netlist, but using S expressions)
* Eeschema can generate this netlist format.
*   Pcbnew can use (automatic identification) the current format or the new format.
*   Cvpcb does not use yet the new format.

portrait setting was being overwritten in dialog_page_settings.cpp, add updatePortrait(), improve comments

    sizes.  Tested with postscript output only.  Required minor file format changes
    to reflect the "portrait" setting.  common/dialogs/dialog_page_settings.cpp
    uses a checkbox but its name is "Landscape", which is inverted from portrait,
    but since it is the more common choice, I used that rather than portrait.
    The tooltip for that checkbox makes it clear.  No portrait mode is supported
    for "User" paper size.

* Remove unnecessary copy constructors from board and module library
  objects.
* Add doClone() method to board and library objects.
* Add comment to class definitions where the default copy constructor
  generated by the compiler was adequate.
* Replace copy method with clone method where applicable.
* Remove DuplicateStruct() function.
* Remove track object copy function.

Eeschema: Fix erroneous message [Read Only] after creating a new project, and obviously the corresponding schematic file does not yet exist (replaced by [no file])

* Remove unnecessary copy constructors from schematic and component
  library objects.
* Add comment to class definitions where the default copy constructor
  generated by the compiler was adequate.
* Add assignment operator to EDA_ITEM, SCH_ITEM, and all schematic
  objects where the default assignment operator generated by the
  compiler would not be adequate.

    Add shim class SCH_BASE_FRAME which introduces the data model SCH_SCREEN
    to the frame class hierarchy.

rather than being rejected.

This feature is very useful for electronics hobbyists who use DIY PCB technology 
(both toner transfer and photoresist methods).
Also width correction may be useful for PCB designers who take care of track width etching.
This patch also fixes some minor PS plotting issues.

Eeschema: add compil option in sch_field.cpp to go back to old behavior for field texts justifications (this option is not activated)
Note: only vertical texts have a modified behavior.
Minor other changes.

* Move SCH_ITEM::Place() code into SCH_EDIT_FRAME so schematic item
  objects no longer have any knowledge of the schematic frame window
  or undo/redo containers.

Minor other enhancements and code cleaning.