Pcbnew: prepare work on new algos for connections calculations.

the GetPosition() and SetPosition() changes.  It also starts towards making m_Orientation
and m_Thickness fields private with accessors, but does not complete this latter goal.

Pcbnew: Fix issue in Undo/Redo command: for very large boards ( > 20000 items) this command could take a long time. Now fast.

Eeschema: fix crash in intermediate netlist generation when a component has no pins (like logos or images).
Pcbnew: texts in dimensions can be now moved.
Gerbview: fix incorrect number of layers  in export to pcbnew function.

- D_PAD members converted;
- style improved;
- GetPosition made returning value, added SetPosition;
- highly experimental, test it please!

* Fix bug in hierarchical searches using sheet path pointers which are
  destroyed on every search.  Use human readable path as last sheet found
  in test to prevent comparison of deleted pointers.
* Fix a bug in SCH_COMPONENT::Matches() that would prevent searching for
  pins if the search all fields flags was not set.
* Fix a bug in SCH_COMPONENT::Matches() to use the sheet path to perform
  the comparison to the correct reference designator and unit number.
* Fix wrapping in sheet path and sheet path list MatchNextItem methods.
* Push search methods down to EDA_ITEM object so advanced searching can
  be performed on all items derived from EDA_ITEM.
* Add virtual method to EDA_ITEM object to test if item supports replacing
  text.
* Replace switch statement magic numbers in Eeschema socket connection code
  with Pcbnew for improved readability.

PCB_ITEM: GetPosition -- removed reference
load/save length in config

Some code restyling: VECTOR_PCB is an array. Cleanup uncontrolled definitions of abs, max, etc. max is now overloaded function and MAX is a macro.

Nanometric work. Design rules, D_PAD (except m_Pos) is now in new units. Metric files can be loaded w/o KICAD_NANOMETRE flag set but saved only with this flag, this could help to gain some compatibility during transition process. ifdef'd code is somewhat minimized by using transition macros. Some potential code bugs are commented.

Fix bug 880132 (Justify not correct)
Note: justifications are now always relative to the text, in libedit (as before) and schematic editor:
if rotated, justification is rotated, because in Pcbnew rotation can have any value.

* Move the component library save file creation and write error dialogs
  into the appropriate frame object.
* Change the save component library and document definitions take an
  OUTPUTFORMATTER object instead of a file name.
* Change the component alias save document definition function to take
  an OUTPUTFORMATTER object instead of a file handle.

Metric KiCad work continues. Partially processed D_PAD class. It is still need to be tested including all these import and export procedures...

Pcbnew: remove useless code.
Doc: remobe obsolete reference to MINIZIP (which do not exist now)

* Replace C malloc() and free() functions with C++ new and delete
  operators or the appropriate STL container.
* Add option to end mouse capture function to skip executing the end
  mouse capture callback.
* Lots of coding policy and Doxygen comment goodness.

Add minor enhancements.

General design rules tab converted to nanoscale. A bit of refactorisation in via sizes. And build key is KICAD_NANOMETRE not KICAD_NANOMETRIC (as I stated in previous commit).