Add weapons/tool selector

[danielduner]

I would suggest adding some sort of weapons and tool selector to the game.
For example using the number keys to select the current weapon/tool in use.

A crude example:

1. Standard gun
2. Pump (for sucking up money)
3. Rail (for building rails)
4. Wrench (for repairing and upgrading buildings)
   (Note that this list is a an example, not an actual suggestion. Specific weapons and tools can be discussed in other issues. This issue is only about adding the infrastructure needed for weapon/tool selection.)

This would make it clear to the player what their character can do in the game. It would also provide a possible way of resolving #570, #265, #41 and #118

[eterzenbach]

+1

[andrew-hardwick]

Agreed, would be a simpler interface as well (clicking to do everything).

We would probably need to bump the time loot remains up a significant amount to allow for the time it takes to change weapons

[Flafla2]

Maybe we should use a TF2 sort of approach, where you pick from a myriad of weapons before the game, and use the 1-4 keys to select the weapons in-game.

[danielduner]

Please note that this issue only is about implementing such a system. What to actually put in the system belongs in other discussions!

@eirthepriest
Having a separate "weapon" for collecting money was just a random example, not an actual suggestion.

@Flafla2
That discussion belongs in issue #118

[LordofMaps]

I'm working on this right now. Should be up in a few hours.