Support Colemak-DH keyboard layouts

[hiroshiyui]

I want to add the Colemak-DH keyboard layouts to enhance the ergonomic affinity of this product.

[hiroshiyui]

REMINDER: currentInputConnection.sendKeyEvent(event) will send key events from IME directly via input connection, omit events such as onKeyDown() or onKeyUp(). You won't be able to simulate physical key events easily.

[hiroshiyui]

REMINDER: currentInputConnection.sendKeyEvent(event) will send key events from IME directly via input connection, omit events such as onKeyDown() or onKeyUp(). You won't be able to simulate physical key events easily.

Clarification: In Android IME, the ultimate end to input text field is InputConnection. Either physical keystroke or soft/on-screen key button click-down is doing the same task logically.

When libchewing's pre-edit buffer isn't empty, libchewing is taking responsibility to handle keystrokes (either hard or soft), otherwise InputConnection should handle string or character, commit any valid input to the target text field.

[hiroshiyui]

Perhaps I can create a class like InputConnectionManager or KeystrokeManager to deal with the related business logic.