gitignore - Hide CRM/Core/AllCoreTables.php under 4.3. (The file isn't used in 4.3, but it comes up when switching back and forth between the 4.3 and 4.4 codebases.)

This is an improvement on CRM/Core/DAO/listAll.php, wrapping in a class
and making the table names available as well.

 * Fetch code with "gitify"
 * Make coordinated tags and push them (instead of using post-commit hook on single repo)
 * Extract hard-coded references to sf.net
 * Split into smaller functions (which are more explanatory and easier to toggle for testing)
 * Document configuration file format
 * Rename executable variables (e.g. $php => $cmd_php)
 * Use "set -ex" to catch errors