Pcbnew: drag functions: serious cleanup and better code. Use now the connectivity functions to find tracks connected to pads,
and therefore  tracks are now dragged when a end point is inside a pad, not necessary on the pad position.
However, drag functions still need more cleanup.

Pcbnew: cleanup functions: now, cleanup uses same algorithm as connectivity calculations to detect pads connections, and is faster.
therefore tracks which have a end point inside a pad, but not necessaryexactly  to the pad position are seen as connected, and are no more removed.
Side effect: reconnect to pads option is removed, because it is useless.
TODO: use this algorithm in drag functions.
Minor other fixes

apply DIALOG_SHIM to dialog_lib_edit_text_base and make dialog_lib_edit_pin_base apportion more width for pin name

dialog plot functions: fix compil warnings with wxWidgets 2.8

Removed filename from the BASE_SCREEN class
Scripting support for board plot

Kicad manager: shows now svg files in tree files.
Pcbnew: fix incorrect printing (board out of page) when creating drill map in postscript format ( noticeable mainly for small boards)

  *  serious code cleanup (remove duplicate code)
  *  shows (option in 3D preference menu) the copper items (tracks, zones...)  in 3D, using 35 microns copper thickness.
      However, because there are a lot more3D data to show (roughly 4 times more), this is slower.

connection, no matter if it is originating locally or from the outside
of the host. There is no check in place to discard non-local
connections. The only security against a malicious attack would be
provided by a local firewall, which is not guaranteed to be installed on
every workstation kicad is used on.

I tested this, and a host running eeschema accepts connections on TCP
port 4243 from other hosts on the internet.

A patch to remedy this potentially serious security hole is attached. It
creates the listener on localhost instead. A flag is provided to allow
the creation of sockets on 0.0.0.0 instead, if required. localhost is
the default.

where the 'z' prefix is for size_t arguments.

*) minor beautification

3d-viewer and polygon functions: remove duplicate code about conversion from basic shapes to polygons.