*) for footprint access into *.mod files and 
*) BOARD save/load

The item_io.cpp and ioascii.cpp have been set off to the side for reference
as *.notused, for awhile.

The CMake options USE_NEW_PCBNEW_LOAD and USE_NEW_PCBNEW_SAVE are gone,
this is now the mandatory usage of the LEGACY_PLUGIN.  This should reduce
code maintenance for awhile until the s-expression plugin comes into 
play.  But at least for legacy format, there is not two code bodies
to maintain any more.

A new LEGACY_PLUGIN footprint library caching scheme is in place which 
needs some testing.  It should not be any faster, but might give better 
results in a networked environment if there is *.mod files on the server.

* Remove internal units from BASE_SCREEN and it's derivatives.
* Remove internal units from EDA_DRAW_FRAME and it's derivatives.
* Use build time code to replace internal units conversions.
* Fix scaling bug in page layout sample window that I created in my
  last commit.

* Move all convert from user to internal units into base_units.cpp.
* Remove internal units parameters from all moved conversion functions.
* Revise all source code that calls the moved conversion functions.
* Remove internal units from all dialog text control helper classes.

Kicad manager: code cleaning. Dead code removed and minor fixes. support of new .kicad_brd extension.

* Scale page reference border and title block, grid sizes, and zoom factors
  correctly for nanometers.

Other minor fixes.

* 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.

drawframe.cpp: commit a fix about scrollbars  from lajos kamocsay

* Move EDA_TEXT object into separate header and source file.
* Compile EDA_TEXT class separately for BOARD_ITEM and SCH_ITEM units.
* Compile PAGE_INFO  class separately for BOARD_ITEM and SCH_ITEM units.
* Minor formatting tweaks to Pcbnew s-expression file.
* Move internal unit formatting functions into BOARD_ITEM and SCH_ITEM.

* Fix bug in PCBNEW dialog_pad_properties.cpp that I introduced several days ago.
  The m_Master_Pad stuff is stored in the PCB_EDIT_FRAME's BOARD_DESIGN_SETTINGS,
  not in the FOOTPRINT_EDIT_FRAME's BOARD_DESIGN_SETTINGS (i.e. not stored in 
  the module editor's dummy BOARD).  Now we properly initialize the
  DIALOG_PAD_PROPERTIES::m_Pad_Master reference to the correct master pad
  dope, instead of to the dummy module BOARD's master pad, which is not used.

If enable in preference menu, allow the pan with drag mouse with middle button down.
both unlimited and limited pan is allowed.

Some minor code cleaning.

Enhancements in AddMenuItem (that accepts now a menu type)
Partial use of the Edwin van den Oetelaar's patch (patch not fully working or correct)

But when using raw printing (for linux - 'lpr some_file.ps') the bug gets out.

Alexander.

Instrument saveNETCLASS() with fmtBIU().
Can now round trip to mm board file using LEGACY_PLUGIN in DEBUG build.

*) Allow building without defining 
        USE_NEW_PCBNEW_LOAD & USE_NEW_PCBNEW_SAVE.
	pcbnew/files.cpp would not link.

* Save dialog now supports saving boards to new file format.
* Add CMake option to build s-expression file save.
* Add check to main CMakeList.txt file to make sure nanometers are
  enables when the new file format is built.
* Minor tweaks to object format functions for improved output.
* Rename kicad_plugin.h/cpp to legacy_plugin.h/cpp.

This uses the new LEGACY_PLUGIN, so we can force more usage & testing of it
before ioascii.cpp and item_io.cpp are deleted, along with 
BOARD_ITEM::Save() and BOARD_ITEM::ReadDescr() associated functions.