Implement "add all" command in AdminUserHandler
Add "auth" Command for SteamGuard

This removes the dependencies on a GUI for auth code input and gives
a more admin-friendly method of steamguard auth.

May not be a perfect solution, but things such as threading
problems are unlikely to happen due to the sleeps and very little
write activity.
Remove Unneeded Form
Merge pull request #268 from kxsong/kxsong

Implement "add all" Command in AdminUserHandler
Merge pull request #274 from Lagg/guiless

GUI-less
Added TradeEventType enum

poll() now uses TradeEventType instead of integers.
Make AuthCode Use Default Accessors

Since there is little chance for thread safety issues (given the
low-use nature of the auth command) there will probably never
be any need for locking and such.
Separate Process auth Supprt - Fixes #275
Merge pull request #276 from Lagg/guileast

Separate Process auth Fix, AuthCode Change, Fixes #275