Added function gitflow_require_initialized(), to assert that the gitflow
variables are all set (they need to be set explicitly once).
diff --git a/git-flow-support b/git-flow-support
index 1bdbaed..8a8ac56 100644
--- a/git-flow-support
+++ b/git-flow-support
@@ -13,9 +13,10 @@
 #
 
 gitflow_require_git_repo
+gitflow_require_initialized
 gitflow_load_settings
 VERSION_PREFIX=$(git config --get gitflow.prefix.versiontag)
-PREFIX=$(git config --get gitflow.prefix.support || echo support/)
+PREFIX=$(git config --get gitflow.prefix.support)
 
 warn "note: The support subcommand is still very EXPERIMENTAL!"
 warn "note: DO NOT use it in a production situation."