Added a global home action when TeclaAccessibilityService connects.
Added methods to send global home and back actions.
Use global home and back actions on the HUD selections.
fixes #167
Fixes #169
Added Tecla shield keyboard-based switch event detection.
Uncommented SwitchEvent receiver.
Made switch event provider available in TeclaAccesssibilityService.
Modified single-switch touch interface to use switch event provider.
Handled mapped actions for switch events.
Connected Tecla shield Switch E1 events to switch event provider.
Added switch E2	events to the switch event provider.
Modified SHIELDEVENT_TIMEOUT to send key only if one key is detected.
Added a TODO comment at the location of joystick switch detection.
Add build directory to hold development app builds for testing
Merge pull request #184 from jorgesilva/develop

Add build directory to hold development app builds for testing
Merge pull request #173 from ericwan78/issue-170

fixes #170
Merge pull request #175 from ericwan78/issue-174

fixes #174
Merge pull request #178 from sagarchandarana123/issue169

Fixes #169
Merge pull request #179 from sagarchandarana123/issue167

fixes #167