Introduce a IExperiment interface and port the camera experiment to use it.

The idea is to have multiple experiments recorded in parallel using the
same ExperimentActivity. Is basically working for the camera experiment.
Add very simple accelerometer experiment.
Add some more artwork.
Add simple menu to add/remove sensors and to view running sensors.

Disable settings menu if the experiment does not have options...
Go back to the preview state if no data has been taken.

This also fixes a crash when stop has been pressed to quickly after
start.
Also init an experiment when it is added to a resumed activity.
Rename IExperiment, IExperimenData, IExperimentRunView and RunDataModel.

RunDataModel -> FrameDataModel
IExperiment -> IExperimentRun
IExperimentRunView -> IExperimentFrameView
IExperimentData -> IExperimentRunData
Add an add experiment run button.
Simplify IExperimentRun interface.
Use new Experiment framework in the experiment activity.

Untested.
Make the experiment activity work again.
Further improvements of the experiment framework.
Fix experiment activity.
Fix initial experiment view ratio.
Add experiment listener interface.

Also rename addRun to addExperimentRunGroup.
Fix TODO.
Some more logic fixes.
Rename run button id.
Add an IExperimentRunListener interface.

Move the camera experiment view completely out of of the main experiment
class.
Separate view from the accelerometer experiment run.