ENH: Simplify local Git hook chaining

Add ".hooks-config.bash" to tell the main hooks to chain to our hooks.
Remove the hard-coded "git config" hook chaining.  The new approach is
better because the chaining configuration is versioned with the hooks
that it chains.

Change-Id: I4a3add10395d1113611394d40d2efe9b5210dd4b

.gitattributes

@@ -1,4 +1,5 @@
 .git*            export-ignore
+.hooks*          export-ignore
 .mailmap         export-ignore
 
 *.bat           -crlf

.hooks-config.bash

@@ -0,0 +1,24 @@
+#==========================================================================
+#
+#   Copyright Insight Software Consortium
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#          http://www.apache.org/licenses/LICENSE-2.0.txt
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+#==========================================================================*/
+
+# Loaded by .git/hooks/(pre-commit|commit-msg|prepare-commit-msg)
+# during git commit after local hooks have been installed.
+
+hooks_chain_pre_commit="Utilities/Hooks/pre-commit"
+hooks_chain_commit_msg="Utilities/Hooks/commit-msg"
+hooks_chain_prepare_commit_msg="Utilities/Hooks/prepare-commit-msg"

Utilities/DevelopmentSetupScripts/SetupHooks.sh

@@ -69,10 +69,4 @@ git config hooks.KWStyle.conf "Utilities/KWStyle/ITK.kws.xml.in"
 git config hooks.KWStyle.overwriteRulesConf "Utilities/KWStyle/ITKOverwrite.txt"
 git config hooks.KWStyle true
 
-# Set up hook chaining.
-echo "Setting up ITK hook chaining: prepare-commit-msg, commit-msg, pre-commit"
-git config hooks.chain-prepare-commit-msg Utilities/Hooks/prepare-commit-msg
-git config hooks.chain-commit-msg Utilities/Hooks/commit-msg
-git config hooks.chain-pre-commit Utilities/Hooks/pre-commit
-
 echo "Done."