abideCreate: Do not no-op on different targets and subsequently differen...

Like every other grunt-i18n-abide task abideCreate allows to define multiple
targets for itself. This can be for example the splitting of purely server-side
template translation strings and purely client-side translation strings. This is
in most cases to speed up translation delivery and overall speedcost created by
fetching overly large translation files that would otherwise contain server- and
client-side translations which is entirely unnecessairy bloat and only serves
to increase page-load-times. Also you may have seperate tools to extract gettext
information from your serverside code as from your client-side code.

Example here:

- server-side:
  - templates: nunjucks
  - translation extraction: i18n-abide translations using gettext()
  - builds: po/mo/js/json files for on the fly translation

- client-side:
  - templates: angular templates
  - translation extraction: angular-gettext with good integration into angularjs
  - builds: po/mo/js/json fils for translation post-download on the client

And so to ease the integration with the necessary client-side tools you'd need a
way to translate pot files from the extraction (in this case nggettext-extract)
into po files and then into javascript (here: nggettext-compile).

Note here that the abillity to create *.po-files has been left completely open
to the implementor and therefore needs tooling during build and to not double
the efforts of course.

grunt-i18n-abide basically is a great fit for that. This change only helping it to
become even better!