Missing dvipng package error: making it easier for new users

Hi

New users to Anki may be very confused with the error encountered when attempting to put latex formulae on the cards for the first time and dvipng fails to execute because it is not installed by default.

If this is a general problem, I can think of two possible fixes:

1. change the dependency to depends or,
2. put a more instructive error message in case dvipng fails with command not found. The message could read "Please install the dvipng package with the command "sudo apt-get install dvipng"'. Even better the program could start that installation automatically. (Is this possible?)

I didn't know if this was a bug, so filed it as a question.

Thank you,
Az