* Main gyp files are now standardized as platform/<platform>/platform.gyp.
* Each platform gyp file defines appropriate loop_lib and headless_lib variables.
* Each platform gyp file includes mbgl.gypi, which defines base targets which may be useful to all platforms.
* CI targets are consistent across platforms: `make $(PLATFORM) && make test-$(PLATFORM)`.
* Renamed the "linux" test app to "glfw". It's now built in OS X CI.
* Android build flakiness is fixed.
* iOS CI builds the bench and iosapp targets.
* Mesa version is now in one place.
* CI scripts use bash "strict mode" and correct error handling.
* All build output goes to the build directory.
* Removed vestigial iOS/OS X/Android Travis scripts.
The defaults remains the same: Bay area at zoom 15.
The key, if not supplied, is taken from the environment.
```
Allowed options:
-s [ --style ] URL Map stylesheet
--north degrees (=37.200000000000003) North latitude
--west degrees (=-122.8) West longitude
--south degrees (=38.100000000000001) South latitude
--east degrees (=-121.7) East longitude
--minZoom number (=0) Min zoom level
--maxZoom number (=15) Max zoom level
--pixelRatio number (=1) Pixel ratio
-t [ --token ] key Mapbox access token
-o [ --output ] file (=offline.db) Output database file name
```
* Under the hood, SQLite creates surrogate keys (ROWID) anyway. We may as well take advantage of this and use the surrogates for foreign keys as well, since they are simpler and more efficient than compound foreign keys.
* Create indexes for efficient eviction queries
I regenerated assets.zip so that all file paths have an `assets/` prefix, as the Android AssetFileSource implementation asserts, and removed `TEST_DATA` from the paths.
It's a premultiplied image. This implies that we were misusing encodePNG
in most cases, as we were passing premultiplied pixels which were then
interpreted as unmultiplied. I changed encodePNG to accept premultipled
pixels, and unpremultiply in the implementations.
The callback will be called when any of the resources requested
from the network failed to load.
There is not recovery implemented yet, so the closest thing to
reseting the Map object and reloading all the resources would
be setting a new style.
