moved pn_config.h -> proton/version.h and install it

git-svn-id: https://svn.apache.org/repos/asf/qpid/proton/trunk@1510511 13f79535-47bb-0310-9956-ffa450edef68
added binary include dir to c build; updated proton.c to include proton/version.h

git-svn-id: https://svn.apache.org/repos/asf/qpid/proton/trunk@1510514 13f79535-47bb-0310-9956-ffa450edef68