Fixes error
Only keep setBlockIndexValid entries that are possible improvements
Reject transactions with excessive numbers of sigops
Add helptexts for -whitelist and rpc prioritisetransaction and switch to bitcoin instead of satoshis
Add a new checkpoint at block 295,000

Block 295,000 seems to meet the criteria of a reasonable timestamp and
no strange transactions. 295,000 is the current block height in the
bootstrap.dat torrent provided by jgarzik.
net: add SetSocketNonBlocking() as OS independent wrapper
additional test for OP_SIZE in script_valid.json
script tests: BOOLAND, BOOLOR decode to integer

unlike other boolean checks, arguments >5 bytes invalidate the script
script tests: values that overflow to 0 are true
script tests: value with trailing 0x00 is true
script test: test case for 5-byte bools
script tests: add tests for CHECKMULTISIG limits
remove an unneded .c_str() in OpenNetworkConnection()
CBloomFilter::clear() method
Add missing FindNode prototype to net.h

Also make the argument a const std::string & instead of pass-by-value.
pyminer: Fix memory leak, refactor to be more pythonic, maintainable, and possibly faster

Pull #4483.

Note that pyminer is not currently functional due to the removal of
getwork in cf0c47b.
Merge pull request #4567

f469f79 remove an unneded .c_str() in OpenNetworkConnection() (Philip Kaufmann)
Merge pull request #4584

0430c30 Add missing FindNode prototype to net.h (Wladimir J. van der Laan)
[Qt] small Qt-only include cleanup
Rework block processing benchmark code

* Replace -benchmark (and the related fBenchmark) with a regular debug option, -debug=bench.
* Increase coverage and granularity of individual block processing steps.
* Add cummulative times.