New develop.svn.wordpress.org repository based on the old core.svn repository.

 * All WordPress files move to a src/ directory.
 * New task runner (Grunt), configured to copy a built WordPress to build/.
 * svn:ignore and .gitignore for Gruntfile.js, wp-config.php, and node.js.
 * Remove Akismet external from develop.svn. Still exists in core.svn.
 * Drop minified files from src/. The build process will now generate these.

props koop.
see #24976.

and see http://wp.me/p2AvED-1AI.


Built from https://develop.svn.wordpress.org/trunk@25001


git-svn-id: https://core.svn.wordpress.org/trunk@25001 1a063a9b-81f0-0310-95a4-ce76da25c4cd