defines the SINK capabilities of the renderer.

Something must be done to set SINK and SOURCE differently
add playlist item if URI is supported
file access is not mandatory to create dlna_item_t object

if the dlna_item_t is an URI is impossible to have the file size, but we need to create an item
empty ActionResponse value generation if Action success

if an action results a empty response and succes, the action handler must create the string otherwise it generate an 501 error
new service state variable handler
add the state var handler
Merge branch 'state_var' into integration

Conflicts:
	src/dlna_internals.h
Merge branch 'integration' into integration_dmr

Conflicts:
	src/dlna_internals.h