Change version name behaivour

If we are on the master branch and the tip is being built, we name the
package version HEAD to align with the package naming we used to use.

Other wise use the git describe output.

CMakeLists.txt

@@ -95,30 +95,19 @@ if( GIT_FOUND )
         ERROR_VARIABLE git_branch_error
         OUTPUT_STRIP_TRAILING_WHITESPACE )
 
+    message (STATUS "On branch ${git_branch_output} with tag ${git_tags_output}" )
     # Due to how tags work in Git it's necessary for us to ensure a few things. For a start, if we
     # create a new branch, switch to it and create a tag, that tag becomes visible in the master
     # branch. Make sure if we're on the master branch that we use that in the
     if( "${git_branch_output}" STREQUAL "master" )
         # TODO: Should we include a 6-digit hash here too?
-        set( CPACK_PACKAGE_VERSION "master" )
+        set( CPACK_PACKAGE_VERSION "HEAD" )
     else()
         if( NOT "${git_tags_output}" STREQUAL "" )
-            # Make sure the tag is associated with the current branch. Otherwise we'll use the branch
-            # name instead. The tag and branch schema means we need branches in the format 1.0, 2.0,
-            # etc. and tags in the format 1.0.1, 2.0.1, etc. to match
-
-            string( SUBSTRING "${git_tags_output}" 0 3 GIT_TAG )
-
-            if( "${GIT_TAG}" STREQUAL "${git_branch_output}" )
-                # The tag matches the branch so use the tag as the package version
-                set( CPACK_PACKAGE_VERSION ${git_tags_output} )
-            else()
-                # Tag didn't match so assume it's there in error and use the more generic branch
-                # name as the package version instead
-                set( CPACK_PACKAGE_VERSION ${git_branch_output} )
-            endif()
+            set( CPACK_PACKAGE_VERSION ${git_tags_output} )
         endif()
     endif()
+    message (STATUS "Setting package version to ${CPACK_PACKAGE_VERSION}")
 endif()
 
 # Everything without leading / is relative to CMAKE_INSTALL_PREFIX.