refactor and integrate with aliBuild/alienv

* accept ZEROMQ_ROOT as env or cmake variable to hint at install
    location (used by aliBuild/alienv)
  * added more docs
  * fixed mismatch between module name ZeroMQ and prefix of
    generated variables ZMQ -> ZeroMQ is now the preferred prefix
    (old variables are still available and marked deprecated)
  * the aliBuild zeromq recipe does not install zmq.hpp header,
    so the module searches now for the zmq.h header
    (which is anyways the only one we use)
  * some cosmetic changes
  * add option ZeroMQ_NO_DEPRECATION to suppress deprecation warning

fairmq/CMakeLists.txt

@@ -25,7 +25,7 @@ Set(INCLUDE_DIRECTORIES
 
 Set(SYSTEM_INCLUDE_DIRECTORIES
   ${Boost_INCLUDE_DIR}
-  ${ZMQ_INCLUDE_DIR}
+  ${ZeroMQ_INCLUDE_DIR}
 )
 
 If(DDS_FOUND)
@@ -124,7 +124,7 @@ Install(FILES ${FAIRMQHEADERS} DESTINATION include)
 
 Set(DEPENDENCIES
   ${DEPENDENCIES}
-  ${ZMQ_LIBRARY_SHARED}
+  ${ZeroMQ_LIBRARY_SHARED}
   ${Boost_THREAD_LIBRARY}
   dl
   fairmq_logger

fairmq/test/CMakeLists.txt

@@ -26,7 +26,7 @@ Set(INCLUDE_DIRECTORIES
 
 Set(SYSTEM_INCLUDE_DIRECTORIES
   ${Boost_INCLUDE_DIR}
-  ${ZMQ_INCLUDE_DIR}
+  ${ZeroMQ_INCLUDE_DIR}
 )
 
 If(NANOMSG_FOUND)