datepicker and timepicker added

...java/com/ireallydontcare/viet/posseidon/MainActivity.java

...a/com/ireallydontcare/viet/posseidon/SubjectActivity.java

...ava/com/ireallydontcare/viet/posseidon/data/EventDao.java

...om/ireallydontcare/viet/posseidon/data/EventDatabase.java

.../ireallydontcare/viet/posseidon/data/SubjectDatabase.java

...care/viet/posseidon/fragments/NewDialogEventFragment.java

.../java/com/ireallydontcare/viet/posseidon/model/Event.java

...ava/com/ireallydontcare/viet/posseidon/model/Subject.java

app/src/main/res/layout/activity_subject.xml

app/src/main/res/layout/content_subject.xml

app/src/main/res/layout/dialog_new_event_item.xml

app/src/main/res/values/strings.xml