Merge pull request #1755 from osmosis79/patch-1

Update doc/build-unix.txt
Merge branch 'bip30_harder' of git://github.com/gmaxwell/bitcoin
Do not abort if RPC listening for IPv6 fails

Instead, fall back to IPv4 listening.
Merge pull request #1822 from sipa/fix_ipv6_rpc

Do not abort if RPC listening for IPv6 fails
Bump client version number for 0.7.0rc3
fix signed/unsigned in strprintf and CNetAddr::GetByte()

- I checked every occurance of strprintf() in the code and used %u, where
  unsigned vars are used
- the change to GetByte() was made, as ip is an unsigned char
update comment, secure_allocator is defined in allocators.h
tests for SetCompact and GetCompact of CBigNum
reimplement CBigNum's compact encoding of difficulty targets

Use shifts instead of going through the MPI representation of BIGNUMs.
Be careful to keep the meaning of 0x00800000 as sign bit.
Bump client version to 0.7.0.99 now that 0.7.0 release is final.
Merge branch 'refactor_times' of git://github.com/luke-jr/bitcoin
Reset release notes for release-after-0.7.0
Merge pull request #1812 from jgarzik/misc-07

Two minor generic cleanups done during OP_DROP hacking
Give makefiles 'test' and 'check' targets to compile and run unit tests
Merge branch 'master' of github.com:bitcoin/bitcoin
Trim trailing whitespace for src/*.{h,cpp}
When rejected TX relay due to lack of fees, log full txid
Merge branch 'testdata' of git://github.com/TheBlueMatt/bitcoin
Merge pull request #1717 from Diapolo/Qt_change_TX_display

Qt: show mined transactions at depth 1
Update gitignore and Makefiles for build.h move from src/ to src/obj