Add DEBUG_LOCKCONTENTION, to warn each time a thread waits to lock.
Add DEBUG_LOCKCONTENTION, to warn each time a thread waits to lock.

If compiled with -DDEBUG_LOCKCONTENTION, Bitcoin will print to
debug.log each time a thread has to wait for a lock to continue.

ahmedbodi/poscoin,reddink/reddcoin,coinkeeper/2015-06-22_19-10_cannacoin,joroob/reddcoin,coinkeeper/2015-06-22_19-10_cannacoin,ahmedbodi/poscoin,coinkeeper/2015-06-22_18-46_reddcoin,reddcoin-project/reddcoin,bmp02050/ReddcoinUpdates,ahmedbodi/poscoin,coinkeeper/2015-06-22_19-10_cannacoin,coinkeeper/2015-06-22_18-46_reddcoin,Cannacoin-Project/Cannacoin,reddink/reddcoin,joroob/reddcoin,Cannacoin-Project/Cannacoin,joroob/reddcoin,reddcoin-project/reddcoin,reddcoin-project/reddcoin,bmp02050/ReddcoinUpdates,ahmedbodi/poscoin,joroob/reddcoin,joroob/reddcoin,bmp02050/ReddcoinUpdates,Cannacoin-Project/Cannacoin,reddink/reddcoin,reddink/reddcoin,coinkeeper/2015-06-22_18-46_reddcoin,Cannacoin-Project/Cannacoin,coinkeeper/2015-06-22_18-46_reddcoin,bmp02050/ReddcoinUpdates,Cannacoin-Project/Cannacoin,coinkeeper/2015-06-22_19-10_cannacoin,coinkeeper/2015-06-22_19-10_cannacoin,reddcoin-project/reddcoin,ahmedbodi/poscoin,reddcoin-project/reddcoin,bmp02050/ReddcoinUpdates,reddink/reddcoin,reddcoin-project/reddcoin,coinkeeper/2015-06-22_18-46_reddcoin