Added message when event doesn't have any speakers and bio is clicked

/src/org/osuosl/ocw/Schedule.java: When an event has no speakers i.e. registration, lunch, etc then a "Doesn't apply" message is displayed when the bio button is clicked.
When bio hasn't been downloaded yet and there is no internet connection then a message is shown

/src/org/osuosl/ocw/Schedule.java: If you open an already downloaded event but try to view the bio that hasn't been downloaded yet and there is no internet connection a message saying so and to try again with internet is displayed.
Added TODO remove hardcoded strings

/src/org/osuosl/ocw/Schedule.java: Added reminder to remove hard coded strings.
Merge pull request #2 from markholland/enhancement-14181

Enhancement 14181
Toast message when bio not available

/src/org/osuosl/ocw/Schedule.java: A toast message when the event doesn't have a bio or the bio hasn't been downloaded. In this case the bio view isn't shown and it stays on the description view. Deleted unused methods from enhancement-14181