Allow regexp as options.origin

[alex94cp]

This patch allows specifying an array of allowed origins or a regular expression for that matter in options.origin, eliminating the burden of having to define a function for such simple tasks. This is in answer to issue #42. Now with all unit tests passed.

[troygoode]

thanks for the PR @alex94puchades - would you mind adding a unit test that covers the regexp usage?

[etiktin]

@alex94puchades, the commits don't seem to include the array support.
I see you added it in #47, but then you closed it and opened this PR which seems to be missing it.
Can you please add it?

[alex94cp]

@etiktin Sure, I'm planning to make a PR for that too (it's quite simple). I closed it because of some failing unit tests, which have been addressed in this PR, and I was waiting for this PR to be merged before adding array support (I'm not an expert in git, I'm afraid of breaking things) xD

[alex94cp]

@etiktin This PR has been superseded by #50. It allows options.origin to be a regexp and also an array of string/regexp. I'm keeping this one open so that @troygoode can decide if both PR are good enough to be merged at the same time or suggest improvements for #50 while this one is ready to be merged.

[troygoode]

closing this in favor of #50