return values of socket functions are ssize_t (not int) in compliance with POSIX

deprecated API (zmq_msg_recv/zmq_msg_send) still returns int
Fix V803 Decreased performance. In case 'it' is iterator it's more effective to use prefix form of increment.
    Replace iterator++ with ++iterator. stream_engine.cpp
    http://www.viva64.com/en/d/0165/print/
Fix V815 Decreased performance. Consider replacing the expression 'options.socks_proxy_address != ""' with '!options.socks_proxy_address.empty()'. session_base.cpp 497
Fix V815 Decreased performance. Consider replacing the expression 'peer_address = ""' with 'peer_address.clear()'. stream_engine.cpp 99
Merge pull request #1202 from pavel-pimenov/fix-pvs-studio

PVS Studio small fix
Partial migration to nonrecursive make.
Remove local pgm configuration option, cleanup configure.ac, remove unused Makefile.am instances.
Merge pull request #1208 from pmienk/master

Reduce automake recursion; simplify pgm dependency
Updated NEWS for 4.0.x releases
Updated development master to 4.2.x
Marked TCP and IPC filters as deprecated (ZAP)
Require pkg-config, use pkg-config to pull seek libsodium.
Merge pull request #1209 from pmienk/master

Simplify libsodium inclusion
Correct declaration of HAVE_LIBSODIUM.
Merge pull request #1210 from pmienk/master

Correct libsodium inclusion.
Remove build and runtime dependencies on e2fsprogs and e2fsprogs-devel.
Fix some typos
Fix builds/msvc/Makefile.am to include all properties files in the build

I attempted to fix up the properties files manifests in the Makefile,
but neglected the end-of-line escape characters.  It was good enough
to pass whatever make dist on Linux did, but I had no Windows build
env to test in.  The broken change was in commit de4a442.

Signed-off-by: Dan Mick <dan.mick@inktank.com>
Merge pull request #1212 from dstftw/fix-typos

Fix some typos
Merge pull request #1213 from dmick/master

Fix builds/msvc/Makefile.am to include all properties files in the build