Add DNS seed of open-nodes.org
Improved logging and Decimal support
build: re-add AM_LDFLAGS where it's overridden

using _LDFLAGS replaces AM_LDFLAGS rather than adding to it.
build: fix win32 static linking after libtool merge

Libtool eats the -static flag rather than passing it along to the compiler. To
get the same effect, -all-static is used instead.
Payment request parsing on startup now only changes network if a valid network name is specified.
Merge pull request #4490

575e70c build: fix win32 static linking after libtool merge (Cory Fields)
9a427da build: re-add AM_LDFLAGS where it's overridden (Cory Fields)
Merge pull request #4275

509f926 Payment request parsing on startup now only changes network if a valid network name is specified. (Ross Nicoll)
Merge pull request #4340

33cc907 Add DNS seed of open-nodes.org (kevin)
Merge pull request #4489 from gavinandresen/python_bitcoinrpc_update

Improved bitcoinrpc logging and Decimal support
Refactor common RPC test code to BitcoinTestFramework base class

Inspired by #3956, with a little more flexibility built in.

I didn't touch rpcbind_test.py, because it only runs on Linux.
Print better errors, and add util stop_node() function.