configure: add libsigc++ support
CComponents: add new header file cc_signals.h with some basic members
CComponentsSignals: add signal OnError
configure: move option enable testmenu to enable testing

Testing is also plausible for general usage of other tests or other
experimental code parts.
CComponentsFooter: add member to add button labels via vector
CComponentsSignals: ad signal OnSelect
CComponentsFooter: add members to set or get select a defined button
CComponentsForm: add members to set or get selected items
CComponents: add members to handle object tags

This can help to handle some useful values for any functions
CComponentsForm: avoid segfault, if id is out of range
CComponentsForm: add member to get pointer to selected items
CComponentsButton: add extended properties for button objects

Allows to assign values for events, msg, results. So it is possible
to evaluate/use these properties eg. directly in exec routines.
CComponentsFooter: expand button label structs

Allows assigning of result, msg and alias values with label struct.

NOTE: Old button label struct are compatible but limited only and
not recommended for usage!
Old parameters 'struct button_label' doesn't provide newer parameters.
Missing parameters are filled with default values and must be assigned
afterward, if required.
CComponentsItem/CComponentsForm: add property focus

Specifies that some certain operations especially eg. exec events for
that item are possible.
CTestMenu: remove window close statement
cc_types: add truct type for rc messages with related icon
CComponentsSignals: add signals for exec handlers
CComponentsForm/CComponentsWindow: add page scroll handling

This provides page scroll with up/down, left/right or combined.
Usage of exec() methods with implemented signals allows a
generic implematation of button or other message handling with
signal/slot solutions.

still to do: page cache
CComponentsTimer: add mutex handling, use neutrino log
Change CComponents::clearSavedScreen() from protected to public

Signed-off-by: Thilo Graf <dbt@novatux.de>

Conflicts:
	src/gui/components/cc_base.h