The warning about using `require('mashlib')` should only be given if it is used

[timbl]

The warning

Console.warn("Warning: mashlib's custom implementation of require will be deprecated in the future. Please import mashlib using a build-time bundler, or access the global panes variable when including it as a script."); // Allow require('mashlib')

would be given (a few lined further down) when the function is used, so it goes when you stop using it.

[Vinnl]

Oops, that was certainly the intention, sorry - I'll fix it in a bit.

[Vinnl]

Fixed in 49c16b6.

(I presumed it to be uncontroversial enough not to need a pull request.)