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.

Pcbnew: fixed a double deletion that crashes pcbnew. Starting my work on net classes (moving target)

* Component library objects renamed for improved readability.
* Fields now move when selected in library editor.
* Add copy constructor to all library draw and library component objects.
* Added copy constructor to EDA_BaseStruct.
* Delete base screen in WinEDA_DrawFrame destructor to prevent potential memory leak.
* Fixed memory access bug when replacing and adding a component to library.
* Moved library component block manipulation code into component object.
* Removed all of the global variables used by the library editor main window object.
* The usual code cleaning and refactoring.

* Split out application specific command IDs to prevent unnecessary rebuilding.
* Eliminate duplicate menu and tool bar command IDs.
* Split component library editor and viewer definitions to separate header files.
* More component library and document file merge code.
* A bunch of minor string readability and consistency fixes.

* Create static component library methods to manage library list.
* Rename component library, component, and alias objects to more readable name.
* Use pointer to component instead of root name to prevent redundant library searches.
* Add append message helper to message panel that calculates string length.
* Initial ground work for merging library and library document files.
* Improved component library file load error checking.
* Minor component library editor improvements.

* Add offset and block hit testing to library component objects.
* Improved search for library entries.
* Fixed library component editor component removal and addition.
* Library editor now uses wxUpdateUIEvents for updating all UI objects.
* Added version check to cmake find boost macro.
* Removed unused code in file libalias.cpp.
* Added method to WinEDA_DrawPanel to take mouse out of managed mode.