Reduce badnwidth at low zoom level: 'trick' the map into showing lower zoom levels.
For example, if the map is at zoom level x, show the tiles for x - 4.
I don't do this exactly.
This code has a low/high zoom level switch, at
the high zoom level, behave as before this commit; at the low zoom
level, trick the map into showing very low resolution tiles, so only a
few tiles need loading to cover the map area.
rename HIGH_ZOOM_THRESHOLD
Merge branch 'dev' of https://github.com/garvankeeley/MozStumbler into low-res-tiles

Rename MapActivity to MapFragment
Changed the dependency for SimpleKML to use our mozilla-services ivy repository
Move the network receiver to its own class, and bind its lifetime
clearly to the lifetime of the MapFragment onStart onStop. Add lots of
guards against the activity disappearing on us.
1006 Added extra guards against NPE
Merge branch 'dev' of https://github.com/garvankeeley/MozStumbler into 2-level-low-res

Conflicts:
	android/src/main/java/org/mozilla/mozstumbler/client/mapview/MapFragment.java
	android/src/main/java/org/mozilla/mozstumbler/client/navdrawer/MainDrawerActivity.java
Merge pull request #1005 from crankycoder/features/ivy-repo

@st3fan Changed the dependency for SimpleKML to use ivy
Merge pull request #998 from garvankeeley/2-level-low-res

Reduce bandwidth at low zoom level: 'trick' the map into showing lower zoom levels.
Merge branch 'dev' of https://github.com/garvankeeley/MozStumbler into 1006-npe
Merge pull request #1007 from garvankeeley/1006-npe

1006 Added extra guards against NPE