Add and configure developer setup helper scripts

Configure GitSetup scripts for CMake.  Run them from a single
Utilities/SetupForDevelopment.sh script.

Utilities/GitSetup/config

+[hooks]
+	url = http://cmake.org/cmake.git
+[ssh]
+	host = cmake.org
+	key = id_git_cmake
+	request-url = https://www.kitware.com/Admin/SendPassword.cgi
+[stage]
+        url = git://cmake.org/stage/cmake.git
+        pushurl = git@cmake.org:stage/cmake.git

Utilities/SetupForDevelopment.sh

+#!/usr/bin/env bash
+
+cd "${BASH_SOURCE%/*}/.." &&
+Utilities/GitSetup/setup-user && echo &&
+Utilities/GitSetup/setup-hooks && echo &&
+Utilities/GitSetup/setup-stage && echo &&
+(Utilities/GitSetup/setup-ssh ||
+ echo 'Failed to setup SSH.  Run this again to retry.') && echo &&
+Utilities/GitSetup/tips
+
+# Rebase master by default
+git config rebase.stat true
+git config branch.master.rebase true