cleanup of callback/signal headers

removed old callback/signal headers
removed typedefs
added move constructor
add callbackcontainer as a replacement of slotcontainer
fixed const correctness in callback
finally fixed segfault in new callback class

I think the main error was to store a reference to the signal/callback.
Now I store a copy of it and everything works fine.
Also work on a copy in the invoke method (in signal) so you can safely
remove (disconnect) callbacks from the signal
replaced every occurrence of old signal/slot

The new callback/signal class is now totally integrated in the clanlib
sources. Only the examples and documentation is left over. Will be done
soon.
adopted display examples to new callbackcontainer
adopted 3D examples to new callbackcontainer
adopted CSSLayout examples to new callbackcontainer
removed kate swap file

ups.
adopted Display_render examples to new callbackcontainer
adopted Display_shader examples to new callbackcontainer
dopted Display_text examples to new callbackcontainer
Compile fix for the CharacterController example
fixed const correctness in callbackcontainer
Remove unused CSSLayout includes from clanGUI
adopted Game examples to new callbackcontainer
adopted Game examples to new callbackcontainer
adopted Input examples to new callbackcontainer
adopted Network examples to new callbackcontainer
adopted Physic2D examples to new callbackcontainer