VGMM: Team Fortress 2: The Tenth Class

Team Fortress 2 has 9 classes to play as. But, the game's unused data reveals files of a possible 10th class. Was there supposed to be 10, or was it always 9?

The Tombstone
On one map (needs specification), there is a tombstone that reads "R.I.P. The 10th Class."

The Commander and Civilian
On the TF2 official wiki, there is a page talking about a class called Commander. It was said to be a non physical class that overlooked the map and provided air support. There is also a class listed called "Civilian". It was a gamemode specific class that must be escorted similar to the bombcart from Payload.