SERVER-12092 mongorestore should generate valid "create" command obj

Fixes an issue where fields in the "create" command object generated
by mongorestore could be out of order, such that an invalid command
would be run instead of "create".

This is a manual cherry-pick of changes:
 - 815bb1efe0f5c3f8ae6c5f0eccf6cf96e4936ab8
 - dc1e3b1a0c16b08aa887ec60a3031ec05ad8431f