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
A tchad keyboard has a diacritic rule that converts `=` (U_003D) into a combining macron (U_0304).
A longpress on `»` (U_00BB) was inadvertently triggering the diacritic rule, and outputting the macron.
The longpress code in KMEA and KMW needs to be refactored so they dont confuse key text (U_00BB is decimal 187) with underlying keyCodes (`=` is keyCode 187).
- fix KMW executePopupKey so key code is dictionary lookup instead of parsing the keyID.
- clean up JS call to executePopupKey since it only uses the keyID
