Remove dead code, unused components and duplication

[jgaehring]

We've accrued a lot of dead code already that needs to be cleaned up. Some of this simply consists of commented out code that wasn't working or superseded, as well as methods/functions that aren't being called anywhere. There is also a great deal of stub components and console.log() statements that are being used for testing purposes, but should be replaced with proper tests (see #11).

There are also a lot of components that just aren't being used (eg, Chooser.vue), and others which should probably be replaced, renamed or repurposed. For example, NewObservations.vue should be renamed EditObservations.vue so it can be used more generically. And instead of listing all observations, as Observations.vue currently does, it should be repurposed as a container component, containing the EditObservation.vue and AllObservations.vue components. AllObservations.vue should then take over the role of listing all observations, as outlined in "Modeling the Observations List").

This issue corresponds to #24.

[jgaehring]

This is mostly done for now. Just need to prevent more dead code from being committed to master in the future, and picking off any stragglers as we go.

[mstenta]

(Transferring all issues from old repository. See #92)