collective.recipe.template's input cannot be downloaded

[Łukasz Nowak]

Consider attached buildout.
After running:
bin/buildout
apply-template: Input file '/home/luke/tmp/collective/parts/download-input/template-input.html' does not exist.
While:
  Installing.
  Getting section apply-template.
  Initializing part apply-template.
Error: Input file '/home/luke/tmp/collective/parts/download-input/template-input.html' does not exist.

Of course - the file does not exists, as it shall be downloaded.

It comes from the fact, that collective.recipe.template checks for file existence in __init__, and not in install hook.

I'd like to propose to move such checks to __init__, if needed even create collective.recipe.template[online] version to have standard behaviour.

[Łukasz Nowak (ionowaklukasz)]

As additional explanation - with this patch presented buildout profile will work.

If this cloud be accepted, I will be happy to write tests for this issue and invest my time.