Enhancement: one line import

[Joshua-Jurgensmeier]

In #419 I confirmed that the current build no longer supports a single import statement for all classes.

Personally, I found a single import statement (import ev3dev.ev3 as ev3) to be very convenient in teaching. This way students don't need to understand what an import statement is, they just need to copy-paste that line at beginning of every source file. I understand that, in general, such blanket import statements are bad practice, but it is simpler to teach

Agree, or disagree?