Fixed a couple of issues from the forum

#### Some bind error fixes with the F1 and F4 menus.

There were a some errors that popped up at times. I'm not sure of the exact circumstances, but I do know one is when you bind a key like "gm_showhelp; other_command". This should all be fixed now.

#### Made DarkRP.addF4MenuTab return the index.

There was a post about not being able to use DarkRP.switchTabOrder as addF4MenuTab no longer returns an index as it did in 2.4.3. *I have made this return first.* I did this for a few reasons. While anybody relying on the sheet return will have to modify their code, I argue that:

1. People migrating from 2.4.3 will have less work to do.
2. People are most likely to use the index over the sheet return as it is more useful to them.
3. I've yet to see anyone use the sheet return.
4. DarkRP 2.5.0 has only recently been released. Not a mass number of people have migrated yet.

I'll change it to the second return if you disagree however.

Documentation has also been updated.