[etymology] Catch an unhandled exception

* Catch an unhandlel exception if the user doesn't provide any input
[wikipedia] Check if user provided valid input

* Check if the user provided any input
* Clear trailing whitespace
[meetbot] Catch an unhandled exception

* Check if meeting is running in listactions
[units] Catch unhanlded exception if no user input

* Catch two unhandled exceptions in distance and temp if the user
specified no input.
Merge pull request #484 from Erethon/master

[modules] Catch unhandled exceptions in multiple modules