Iced Coffee-Script doesn't work with --watch

[mindjuice]

In the following change, support for watching coffee files was added, however, iced coffee-script does not work.

11ff9f0

Instead of hard-coding "coffee" into the regex, it would be better if every extension mentioned in the --compilers settings was added.

For example, if you include:

-compilers iced:iced-coffee-script/register,coffee:coffee-script/register

Then the regex would include (js|iced|coffee).

This would future-proof "watch" to work with any new compilers.

[xpepermint]

+1

[jbnicolai]

Good call. Care to prepare a PR?

[kulicuu]

+1

[dasilvacontin]

See #1425.