[plan] Update curl Plan to remove `fix_interpreter` & update styles.
[plan] Update curl Plan to remove `fix_interpreter` & update styles.

This change updates/fixes/removes the following:

* Remove the `fix_interpreter()` helper call on the zsh completion
  generating program. This is a build-time only concern and so the
  source code should be "patched" in the `do_prepare()` phase.
* Add maintainer metadata
* Fix intendation styling to 2 spaces (vs. 4 spaces)
* Re-ordering of the metadata to be more consistent with other Plans
* Remove the call to `make install` in build which should be in the
  `do_install()` phase. However, since this is default behavior, we can
  remove it and prevent this Plan from double-installing (which it was
  doing previously)

Pull request: #449
Approved by: adamhjk

be-plans/be,be-plans/be,be-plans/be,be-plans/be