Merge branches 'master', 'master', 'master', 'master', 'master' and 'master' of https://github.com/e-learning/android-30-2013
Merge branches 'master', 'master', 'master', 'master', 'master', 'master' and 'master' of https://github.com/e-learning/android-30-2013
Add calculator
Merge branch 'master' of https://github.com/e-learning/android-30-2013
Merge branch 'master' of https://github.com/e-learning/android-30-2013
Merge branch 'master' of https://github.com/e-learning/android-30-2013