Implement new Vehicle changes 9/15 update

[awilliamson]

According to http://www.garrysmod.com/updates/ a number of new and interesting vehicle methods have been introduced, as well as weapon methods.

These may be particularly useful to those who wish to create cars or have more control of user weaponry.

I believe we should start filtering interesting articles from the monthly updates to stay ahead of the game. As implementing methods by selecting them from the library as documented on the wiki is very time consuming and a large chunk in one go. The monthly updates allow us to have a more manageable digest and process them quickly to make decisions about inclusion, exclusion or flagging for comments.