Move base map selector to left side

When you rotate an iOS 7 application, a compass shows up in the upper
right corner, which was being overlapped by the layer selector.
Draw white background behind base map selector

The transparent selector made the text hard to read, and setting a
backround color produced square corners rather than rounded ones.

Adapted from http://stackoverflow.com/questions/19138252/uisegmentedcontrol-bounds
Include gps/location icons in the project

These were mistakenly dropped in the transition from the v1 skin to the
v2 skin.
Use default search bar and move GPS button

In iOS 7 our trick to add a button to the search bar did not not look
great. I deleted the search bar, dropped in a default one, and added a
new button to the bottom right of the map view that triggers the
location finding.
Fix up species search bar

The alphabetical index strip on the right side of a table view does not
play nice with a UISearchBar. This is a known issue with no great
workarounds. I updated the background colors and width of the
UISearchView so that it looks as good as possible.
Merge pull request #83 from jwalgran/topic/map-view-ui-updates

Map view UI updates