Merge pull request #553 from hintjens/master

Some changes to building and packaging

builds/msvc/Makefile.am

 LIBZMQ_DIST = libzmq/libzmq.vcproj libzmq/libzmq.vcxproj \
               libzmq/libzmq.vcxproj.filters \
-              platform.hpp msvc.sln msvc10.sln
+              platform.hpp msvc.sln msvc10.sln \
+              errno.cpp errno.hpp
 
 PERF_DIST = c_local_thr/c_local_thr.vcproj \
             c_local_thr/c_local_thr.vcxproj \

configure.ac

@@ -62,9 +62,10 @@ LIBZMQ_CHECK_ENABLE_DEBUG
 # Check wheter to enable code coverage
 LIBZMQ_WITH_GCOV
 
-# Checks for libraries.
+# Checks for libraries
 AC_CHECK_LIB([pthread], [pthread_create])
 AC_CHECK_LIB([rt], [clock_gettime])
+AC_CHECK_LIB([sodium], [sodium_init])
 
 # Set pedantic
 libzmq_pedantic="yes"