Add pending_handlers
Overlay cleanup
Cleanup: Merge PeerFinder API headers into one
Cleanup: Put handout classes and functions together
Tidy up Checker declaration
Don't use callbacks to activate PeerFinder slots
Remove needless functions and inline them

Conflicts:
	src/ripple/overlay/impl/PeerImp.h
Add redirect()
Add send() endpoints
Add overlay timer for autoconnect
Move autoconnect to overlay
Move timer to overlay
Remove unused connect callback
Add sendpeers function to replace send callback
Change connected to return a bool
Remove disconnect callback
Remove Callback
Remove SiteFiles injection from PeerFinder