Added otextensions - Move OTSocket (ZMQ) out of otlib
Add otextensions to packaging
otextension: Install headerfile
Merge pull request #190 from lclc/otextensions

otextensions added - Move OTSocket / ZMQ in new lib
Fix up otextensions Makefile mods.
Merge pull request #199 from randy-waterhouse/develop

Fix up otextensions Makefile mods.
Removed unnecessary includes
Reordered includes as per best practices
Changed angular brackets to quotes
Fixed missing include on Linux
Another fix for Linux
Removed some commented out lines to get Travis building again.
Re-added <cerrno> to OTLog.cpp
Correct cerrno this time. *sigh*
Re-added <algorithm> to OTPseudonym
Added cerrno to OTPaths
Added cstdio to OTString
Removed commented-out unnecessary include files
Reinstated wordexp.h in OTString
Re-added missing included files to OTKeyring.cpp