Add button to home view to search API by current location.

Gets current location from Location Services, reverse-geocodes it, then puts the returned address into the text search field.
Put contact selector next to text edit field.

    Removes from home view option to search by current location, and moves contact selector butt
    to where the search button was next to the text edit field (and removes extra button to star
    search).

    Puts location-finding logic into tab bar activity, for later use in getting directions.
Put a little breathing room back into home view
Enable current location on map view
Optionally show directions from current location.

Before transitioning to directions view, prompt user what origin to use
(either entered address or current location), then show directions for selected
origin.

In case current location selected but location services disabled, will prompt
to enable location services, then re-query once location found.
Fix typo and invert test condition
Merge pull request #38 from flibbertigibbet/feature/use-current-location

Feature/use current location