Add test cases for Clock

Add test_clock_add_alarm_multiple_times
Add clock test cases

test_clock_set_alarm_repeat;
test_clock_set_alarm_snooze;
test_clock_set_alarm_sound;
Address pep issues for #432

Address pep issues for #432.
test_clock_add_alarm_multiple_times.py
test_clock_set_alarm_repeat.py
test_clock_set_alarm_snooze.py
test_clock_set_alarm_sound.py
Re-implement tap on value selectors for #432

Address issues for #432.
test_clock_add_alarm_multiple_times.py
test_clock_set_alarm_repeat.py
test_clock_set_alarm_snooze.py
test_clock_set_alarm_sound.py
Move local parameters to class for #432 and add test case for #440

Move local parameters to class for #432 and add test case for #440
test_clock_set_alarm_repeat.py
test_clock_set_alarm_snooze.py
test_clock_set_alarm_sound.py
test_clock_set_alarm_time.py
Remove Tab for #432

only test_clock_set_alarm_sound.py is modified
Added test_settings_passcode.py for #477
Disable passcode in cleanUp(). #477
Eliminated the domain from URL. #503
Eliminated the domain from URL. #503
Modified the _passcode_enable_locator.
Update and re-enable the test_settings_cell_data
Remove logic in test_settings_cell_data due to more robust test setUp
Merge remote-tracking branch 'upstream/master' into fix_settings_cell_data
Add more verification steps for #432

Add manifest.ini
Add more verification steps
Remove unlock screen
Merge branch 'master' into issue_503
Test for enabling/disabling Airplane mode
issue #456
remove extra lines #432

removed extra lines and move time.sleep(1) to function
Merge remote-tracking branch 'mozilla/master' into issue_456
	gaiatest/tests/settings/manifest.ini
changes for #432

add alarm_close" to clock_object and use it in set alarm repeat;
Modify the verification for adding multiple alarms;