Removed JRuby exception details showing up in CalabashException

JRuby stack traces are ususally not very helpful as it contains only the
evaluation failed message. We are getting only the exception message
from JRuby and not the stacktrace
Fixing keyboard throwing exceptions when no keyboard available
v1.2.0
Vishnu, Melanie | Adding Keyboard test
Added support for deriving from calabash runner
Vishnu, Melanie | Building with cal.xcconfig
changing gitignore
Adding .classpath entry for commons
v1.2.1