Fix targeted powers when clicking on actionbar; Change how touch input works

- b682aa6 takes a more programmatic approach to some copy/pasted code
- f80a7a9 is a partial solution for #1168
- 9e39066 is an implementation of the idea discussed [here](https://github.com/clintbellanger/flare-engine/pull/1169#issuecomment-53847045). I don't think that press/hold behavior functions well for this type of game, nor is it easily discoverable. If others disagree with this method of handling touch input, I'll remove this commit from the pull request.
No, this is correct. It implies that the action variable contains two members:
- The power id to be activated, `action.power`
- The target as an FPoint, `action.target`