* 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.

* support for 3 terminal regulators
* add a data file management to store parameters for regulators ( name, vref value, Iadj value, type)
Needs some refinements, but it is already very useable.

 Commit dialog page setting patch from Alexander Zakamaldin

* Add s-expression Format() function to all objects derived from
  BOARD_ITEM.
* Add s-expression Format() function to base objects as required.
* Add functions to convert coordinates from base internal units
  (nanometers) to millimeter string for writing to s-expression
  file.
* Add temporary dummy conversion functions to prevent link errors
  until schematic and board object and action code can be separated
  into DSO/DLL.
* Add CMake build option to build Pcbnew with nanometer internal
  units.

compile base_screen.cpp separately for {pcbnew,cvpcb} and eeschema, so we can diverge internal units at compile time, not runtime

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.

Remove obsolete foldr resources/icons.
Updates svg icons in folder resources.

Fix minor other issues.
Remove unused files.

Eeschema: optimize import of footprints names ( .stf files) that was time consumming with large designs.