Merge pull request #169

1160505 fixed checkpointing bug (Riccardo Spagni)
c4d6658 quick hacky fix for broken TXT reads (Riccardo Spagni)
2322a94 cleaned up OpenAlias messages in simplewallet (Riccardo Spagni)
1663089 MoneroPulse log wording tweaks (Riccardo Spagni)
1d515b8 boost 1.56 kindly (and officially) patched in msys2 by Alexey Pavlov (Riccardo Spagni)
e3d2400 forgot to add connection context to log line (Riccardo Spagni)
6f7ed13 moved checkpoint log level (Riccardo Spagni)
3e644c2 moved file checkpointing log output to log1 (Riccardo Spagni)
0e1b7c9 moved non-critical p2p errors to l2 (Riccardo Spagni)
a3332e7 remove dangling upnp port mappings, updated miniupnpc (Riccardo Spagni)
6b9a7fc fixed unbound static lib on mingw as libunbound.dll.a (Riccardo Spagni)
bba217a remove pthreads, successfully tested on gcc 4.9.1 without pthreads (Riccardo Spagni)
18281f4 remove dangling upnp port mappings, updated miniupnpc (Riccardo Spagni)
9130e41 fixed unbound static lib on mingw as libunbound.dll.a (Riccardo Spagni)
8c37823 remove pthreads, successfully tested on gcc 4.9.1 without pthreads (Riccardo Spagni)
dns async ipv4 test
more work toward async dns