Add EDA_BASE_FRAME::Show() and call SaveSettings() only from there for all derived wxFrames.  Remove calls to SaveSettings() elsewhere.

Remove g_LibraryNames and all supporting infrastructure from pcbnew.  FP_LIB_TABLE is now local to major wxFrames.

Pcbnew: fix bug #1272714 . Code cleanup: use 2 different enums for pad shapes and pad drill shapes. Remove never used pad shape.

D_PAD::GetNetname() and D_PAD::GetShortNetname() were moved to BOARD_CONNECTED_ITEM. Now they use the net name stored in NETINFO_ITEM.
Moved some one-line functions from class_board_connected_item.cpp to class_board_connected_item.h.
Added a copyright notice, moved Doxygen comments from class_board_connected_item.cpp to class_board_connected_item.h.

I have some doubts if changes introduced pcbnew/dialogs/dialog_pad_properties.cpp do not break anything, but I could not find a test case that breaks the pcbnew.

Performed tests:
- changed pad's net name from empty to existent - ok, name was changed
- changed pad's net name from empty to nonexistent - ok, error message is displayed, net name stays empty
- changed pad's net name from existent to empty - ok, net name became empty
- changed pad's net name from existent to nonexistent - ok, error message is displayed, net name is not changed
- (re)reading netlists, including net changes - fine, changes are applied, but empty nets are still kept
- loaded pcbnew/pcad2kicadpcb_plugin/examples/CK1202_V1.pcb to test P-CAD import plugin - ok, net names are correct
- imported an Eagle 6.0 board (Arduino Uno; http://arduino.cc/en/uploads/Main/arduino_Uno_Rev3-02-TH.zip) then saved in .kicad_pcb format and reloaded - ok, net names are correct
- saved demos/video/video.kicad_pcb in legacy format and then loaded it again - ok, net names are correct

Dialog fp plugin option: Fix compil issue under gcc 4.4 (does not happen with 4.6 and later) about an overloaded function.

dialog fp lib table display not updated (Windows specific) when an option is changed from the lib table option editor
overloaded function in dialog_fp_lib_table.cpp not compiled with gcc 4.4.7 (try to fix Bug #1262002).
specctra_export.cpp: set min dist to find segment ends when building the board outline to 2 microns (should break anything, but should be enough to fix rounding issues when creating/importing board outlines with arcs)

Minor change: Eeschema+Pcbnew: display timestamp in edit dialogs (for footprints, sheets, components)

* Replace illegal file system characters when reading legacy libraries to
  prevent FPID parsing errors and allow saving to PRETTY file format.
* Create validator to filter illegal file system characters from footprint
  name text edit controls to prevent issues when saving to PRETTY file format.
* Add missing source file licenses and some minor coding policy fixes.

Pcbnew: Code cleaning and bug fix in autoplace functions
Dialog exchange footprints has now a separate button to update the .cmp file, only on request.

FIX: unique renaming of eagle footprints by substituting illegal : and / with URL encoding technique.
ADD: window resize border to DisplayError() windows.

* Make spacing between controls and dialog frame consistent.
* Use default size to allow wxWigdets to determine optimal dialog size.
* Set OK button as default so return key works properly.

* Use std::swap for PCB_LINE_T items in SwapData().
* Use std::swap for PCB_MODULE_EDGE_T items in SwapData().
* Add assignment operator to EDGE_MODULE object.
* Move code from copy method to assignment operator.
* Minor coding policy fixes.

*) Save library nickname in APP so upon module editor re-entry last is re-used.
*) Fix bug editing fp-lib-table Description field.

*) Move button handlers to LEFT MOUSE CLICK from COMMAND events, so wxGrid focus is not lost.
*) Sketch out the concept of COW support for the GITHUB_PLUGIN in its @todo.

more DIALOG_FP_PLUGIN_OPTIONS work, make PROPERTIES a map instead of a hashtable for alphabetical iteration.

*) Use it on 3 grids total in DIALOG_FP_PLUGIN_OPTIONS and DIALOG_FP_LIB_TABLE.
*) Fix bug when pasting "(fp_lib_table" text into FP_LIB_TABLE.

template<> -> template <>
Some more reformatting according to uncrustify results.