lib/android: intro the `toast` module

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
lib/android: intro the `notifications` module

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
android: add super classes to `NativeActivity`

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
lib/android: intro the `ui` module

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
examples: intro app.nit Android UI test

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
calculator: add an icon

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
calculator: intro android UI

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
jwrapper: no whitespace before end of line

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
lib/collection: improve documentation of `has_all`

Signed-off-by: Jean Privat <jean@pryen.org>
lib/collections: add `Collection::has_exactly`

Signed-off-by: Jean Privat <jean@pryen.org>
Merge: Android UI, notifications, toasts and calculator

This is the base of a the API for native controls on Android. As such, is it a work in progress.

Example applications:
* app.nit UI test
* Calculator

Features still to do:
* Wrap `ViewGroup`s with Nity classes. This will allow us to make all native classes private.
* Implement `ListView` and other useful views.
* Offer more notifications features from later APIs.

Pull-Request: #934
Reviewed-by: Jean Privat <jean@pryen.org>
Merge: jwrapper: no whitespace before new line

Pull-Request: #938
Reviewed-by: Jean Privat <jean@pryen.org>
Merge: new method `has_exaclty` on collections

This is used to compare collections without taking the order into account.

Pull-Request: #940
Reviewed-by: Alexis Laferrière <alexis.laf@xymus.net>