Show nodeid instead of addresses (for anonymity) unless otherwise requested.
Improved getblocks logging.

Conflicts:

	src/main.cpp
Add net2 debug option
Correct logic so that not both lines are displayed

e.g.:-
2014-02-25 06:56:39 received getdata (1 invsz)
2014-02-25 06:56:39 received getdata for: tx 8e2e08d1d851eb1ac800e814796dd7b86fd6d3a8fad41d5bdcb873ac6f4aba8d
Add CaughtUp() function (needed by later commits)
Record timings of block download process and display count of block invs received.
Fix many orphan problem. Don't getblocks following orphan reception. (Needs CaughtUp())
Don't getdata blocks if an inv is received that wasn't requested (getblocks).

Also, show invs being received (and indicate whether we have the block or not).
Better logging of ProcessMessages() progress
Show downloaded block size and time taken to download.
Replacement stalled block logic. Depending on the situation, it will either disconnect
the peer (as previoous behaviour), or it will reselect a syncnode (e.g. when 500 blocks
have been received from the syncnode).
indentation
Rename MarkBlockAsReceived to MarkBlockAsRequested to reduce confusion.
Force selection of a new syncnode since the current syncnode is about to stop sending blocks.