Instance request improvements

* One request per app start
* Request instance on logout
* Re-request instance on login
Formatting
Merge pull request #44 from maurizi/change-missing-photo-imagename

Rename ic_action_search to a sane name (better image coming soon!)
Merge branch 'master' into fix/35/instance-logins

Conflicts:
	OpenTreeMap/src/org/azavea/otm/App.java
	OpenTreeMap/src/org/azavea/otm/rest/RequestGenerator.java
Merge pull request #43 from OpenTreeMap/fix/35/instance-logins

Instance & login request improvements
Update eco benefits display

Fixes #27
Uses new instance eco field definition structure
Merge pull request #46 from OpenTreeMap/fix/27/eco-display-fix

Update eco benefits display
Stop polling for list updates on activity change

When the list tab is not visible either through tab switch or app
hide, stop checking for updates.
Auto formatting
Remove commented code

We don't impose filters when finding a tree under a map click, on
the assumption that the canopy and filter layer are always displayed
Merge pull request #51 from OpenTreeMap/fix/45/too-much-list-http

Stop polling for list updates on activity change
Scale and crop the tree thumbnails for popup

This is an imrprovement in so much as the pictures do not stretch
the parent popup view when they are in different orientations, but
could still use some styling work with padding and so forth.  Waiting
for a style overhaul before actually touching xml layouts too much.
Merge pull request #52 from OpenTreeMap/fix/47/photo-crop

Scale and crop the tree thumbnails for popup
Auto-formatting
Get address search extent from instance info endpoint
Fix changing enter button -> search button for location search
Add chevron to map vignette

Fixes #48
Make map look like you can click to edit.
Merge pull request #53 from maurizi/fix/location-search

Fix location search
Merge pull request #56 from OpenTreeMap/fix/48/chevron-map

Add chevron to map vignette
Use an appwide theme at a higher api level

Holo is only valid at API level 11 and above, which I now target.
This gives a light background with dark text on inputs.  Future
commits will consolidate the theme styles and provide a fallback
for lower SDK levels.