Revert "Added CRC checks to "Lurking in the Shadows.esp" navmesh messages. Also minor other stuff."

This reverts commit abedf57f9fcb1e0d7e50092c64f00f16ed8810bf.
Revert "Removed code from trunk and added redirection message to the GitHub repository."

This reverts commit a5e9c49a5d34cbb20f1653434882727b2bbc4087.