ui_interface: remove unused NotifyBlocksChanged signal
Create new signal for notification of new blocks.  Use w/ -blocknotify
Fix a few "Uninitialized scalar field" warnings

Fix a few warnings reported by Coverity.
None of these is critical, but making sure that class fields are
initialized can avoid heisenbugs.
cleanup include of assert.h
Merge pull request #4777

8bdd287 Fix a few "Uninitialized scalar field" warnings (Wladimir J. van der Laan)
build: Remove message about Ubuntu 13.10 when no boost sleep implementation found

It's only confusing people into thinking that they should mess with
boost versions, which should not be necessary to get bitcoind to work.

If there is a bug in the build system with autodetecting boost it needs
to be solved not worked around.
rpc: Compute number of confirmations of a block from block height

Currently this uses a CMerkleTx, but that makes no sense as we
have the CBlockIndex available. As noted by @jgarzik.
Move CMerkleTx to wallet.cpp/h

It is only used by the wallet so it has no place in main.
Merge pull request #4599
missing include boost/algorithm/string/replace.hpp
Merge pull request #4788
Merge pull request #4778
Replace weird characters by normal spaces
Merge pull request #4781

187115c cleanup include of assert.h (Philip Kaufmann)
Merge pull request #4789

bac5586 Replace weird characters by normal spaces (Pieter Wuille)
changed field types in some structures to equivalent unambiguous types

Conflicts:
	src/core.cpp

Rebased-By: Wladimir J. van der Laan
Github-Pull: #4180
Create build-aux/m4 dir. Move m4 scripts for out-of-src builds.
Remove pkg.m4. Update .gitignore.