Big cleanup of sourcetree root structure, added Documentation subfolder, moved packaging stuff for osx and windows (nsis) to packaging.

* Create single event handler for grid size events.
* Fix all frame windows to use new grid size event handler.
* Use offset relative to ID instead of ComboBox index to save last grid size.
* Move last grid size load/save setting into WinEDA_DrawFrame.
* Add equality and assignment operators the GRID_TYPE.
* Add current grid helper methods to BASE_SCREEN.
* Add GetPins helper to LIB_COMPONENT to replace GetNextPin where applicable.
* Add AppendMsgPanel helper to WinEDA_DrawFrame.
* Improve rounding for display of coordinates when millimeter units are selected.

fixed a minor problem in pcbnew compiled in DEBUG mode, that prints a lot of error messages when loading a board

Fixed problems in libedit and crashes when no component loaded

* Replace component library editor new component dialog using wxFormBuilder.
* Rename component library draw items to conform to current coding standards.
* Add GetWidth() method to component library draw objects.
* Add regular expression key word search capability to component library object.

pcbnew: more about netclass work

* Library component draw items now stored in Boost ptr_vector.
* Updated draw item object comparison to include greater and less than condition.
* Moved set parts per package code from component edit dialog to component object.
* Moved set alternate body style code from component edit dialog to component object.
* Tweaked component library file draw item sort order for improved file readability.
* Documented component object draw item sort ordering.
* Moved plot code to the appropriate library component and draw item objects.
* Fixed compiler type conversion warning in plot_common.h.

* Component library viewer restores state between uses.
* Fixed automatic zoom calculations in library viewer.
* Make library entry list dialog restore previous selection.
* Fix bounding box calculation for vertical field and text draw objects.
* Changed library draw object comparison to test for greater and less than.
* Initial preparation for merging separate library component draw item lists.

* Eliminate external direct manipulation of component draw item pointer.
* Add draw item remove, add, and locate methods to library component object.
* Remove redundant locate pin, field, and draw item code.
* Fix add new pin drawing bug that left initial pin draw in place.
* Improved best zoom calculations for small components.
* Library component bounding box calculation now includes fields.
* Removed unnecessary header file "libcmp.h".
* Fixed potential locate draw item bug in library editor hot key handler.