The default sample languages left out a region for English, so it wasn't appearing in the toolbar UI.

Tweaks the new return value's behavior.

Mostly incorporates the 'only set active keyboard if old one was removed' request, though there's an occasional issue with the active keyboard mysteriously persisting.

`removeKeyboards` API function validation + enhancement.

Update to Android Studio and Gradle 3.0

Extended the test slightly and implemented the 'return true/false' component mentioned in the issue.

addKeyboards parameter property:  'language' -> 'languages'.

Sets init param 'attachType' to 'auto' for all devices.

Per Android Studio 3.0 [Release Notes](https://android-developers.googleblog.com/2017/10/android-studio-30.html)

-Update gradle version
-Change deprecated `compile` dependencies to `implementation` or `api`
-Change maven repositories to google (triplet plugin still on maven)
- Update readme instructions for using the engine

[Mac]: Prevent Keyman processing command keys

Cherry picked a few small changes from "mac compatibility" branch to fix bug whereby command keys were sometimes causing characters to be output.

name/id mismatch in MergeKeyboardInfo

Move KMBM variable out of KV member in keyboards to match compiler behaviour

Fixup attachType for web debugger in Keyman Developer

Addresses the recent iOS image asset requirement change.

Removes the 'free' set of asset images and attaches the newly required 'marketing' 1024x1024 icon.  Addresses #371.

Refactor longpress logic so key text is not confused with key code

`String.fromCharCode()` has a limitation to Unicode characters in the BMP. Change to `String.kmwFromCharCode()` to handle entire Unicode range.

Also clarified how default key codepoints are processed.

KeyboardHarness changes:
- Change text area font on keyboard change
- Added U_10481 to test longpress keyboard.
- Remove test tchad keyboard

Update comments explaning how control codes U_0000 to U_001F and U_0080 to U_009F are suppressed.

Also updated longpress test keyboard to test control codes.

* Fix accessing AltGr shift layer
* Fix AltGr OSK layer to display as "Alt Ctrl"
* Fix how Unicode control characters are filtered out, so U_00A0 can be displayed

Rework of KMW keyboard registration + default keyboard selection.

Mobile default-layer shifting regression fix