Fixes #750 

Currently, Keyman for Android targets SDK version 25 (Nougat). 

This PR targets  the latest Android API and updates all the Gradle dependencies to the latest. This will remove some lint Obsolete warnings.

Sample and Test projects needed to add 
```
implementation 'com.android.support:support-v4:27.1.1'
```
to ensure all dependencies use the same version.

[Web] Basic mnemonic keyboard support

[Mac] #770 Added logic to hide OSK when Keyman is no longer active IM.

[windows] Keyman Desktop Setup restarting Windows pathway is a little unclear if user chooses not to restart

[windows] Implement IKeymanKeyboardFile.DefaultHotkey

Fixes #374, Keyman Desktop restarting Windows pathway is a little unclear if user chooses not to restart

[windows] Fixes a crash in Keyman Configuration if the focused element has no id

[android] cleanup console log

Fixes #748

* Remove nearly all uses of `Log.d()`
* Disable `window.console.log()` calls in `keyboard.html`

[Mac] #768 - Added "Use verbose Console logging" option.

[windows] Add script lookup to "Add Language" dialog so end user experience is improved.

[Web] CODE_BEEP in stores

[Android] Update string handling for PackageProcessor

Merge pull request #831 from keymanapp/windows-configuration-crashes-when-ampersand-in-keyboard-name-5507

[windows] Fixes ampersand in keyboard name can cause Keyman Configuration to crash

[windows] Fixes crash starting Keyman Configuration if high bit is set in underlying keyboard id

Fixes sillsdev/keyman-issues#5507, ampersand in keyboard name can cause Keyman Configuration to crash

[windows] Fix sporadic crash in Keyman when updating keyboard icon in OSK