Fixes error
Only remove actualy failed blocks from setBlockIndexValid
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.
Remove tx from AlreadyAskedFor list once we receive it, not when we process it.
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
Introduce option to disable relay/mining of bare multisig scripts in TX outputs

First and foremost, this defaults to OFF.

This option lets a node consider such transactions non-standard,
meaning they will not be relayed or mined by default, but other miners
are free to mine these as usual.
script tests: add tests for CHECKMULTISIG limits
Update README.md

Added two modifications to make the descriptions more clear.
qt: Make error message for failed export a little friendlier

Closes #4528.
Merge pull request #3939

3da434a Introduce option to disable relay/mining of bare multisig scripts in TX outputs (Jeff Garzik)
[Qt] Fix thin space in URI
Merge pull request #4563

027dcdc [Qt] Fix thin space in URI (Cozz Lovan)