Correctly handle screen rotation on iOS
Merge branch 'master' into lifecycle
Makes Android Tangram class a modular view that is simple to add to an Activity; Tangram now extends View and acts as its own Renderer and GestureListener
Ask Android to preserve GL context on pause, preventing crashes from invalidated GL resources; We'll need a fallback for when this can't be satisfied, but for now this solves GL-related crashes on all tested devices
Prevent TileManager from trying to get data from a tile that failed to load
Add a mutex member to DataSource and lock it when modifying the tileStore concurrently
Merge branch 'master' into lifecycle

Conflicts:
	android/src/com/mapzen/tangram/MainActivity.java
Allow Android app to rotate screen without re-creating Activity
Modify View to handle screen rotation more consistently; View now stores the current screen dimensions and scales itself such that tiles are 256 x 256 px in screen space (at their base)
Fix zoom value clamping
Prevent re-instantiation of top-level tangram members
Track ShaderPrograms in a static list\n\nEnables rebuilding shaders after GL context loss
adding core base files for raspberry Pi
editing README to install C++11 compatible compiler
Add Android lifecycle hook into teardown()
Manage VBO GL resources through static list
Merge branch 'master' into lifecycle
adding libtess2 compiled on RPI
static lib
erasing share lib