Multiple Rewrite Patterns and Substitutions

[tasarsu]

Issue #, if available:
#121

Description of changes:
REWRITE_MATCH_PATTERN and REWRITE_SUBSTITUTION values can be written like JSON Arrays.
So multiple rewrite rules can be applied.

For example;
REWRITE_MATCH_PATTERN:
["//thumb/g","//small/g","//large/g"]

REWRITE_SUBSTITUTION:
["/300x300/filters:quality(80)","/fit-in/600x600/filters:quality(80)","/fit-in/1200x1200/filters:quality(80)"]

Checklist

• 👋 I have run the unit tests, and all unit tests have passed.
• ⚠️ This pull request might incur a breaking change.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[dougtoppin]

@tasarsu thanks for your contribution, we are going to review it and try a few tests, we appreciate your work and will let you know what we find

[dougtoppin]

@tasarsu Thanks for your submission. We created a feature branch for it called feature/rewrite-pattern.
We may make some changes to it for adding unit tests and potentially other changes but we wanted to let you know that we are evaluating it.

[tasarsu]

Thank you for the update @dougtoppin

I have developed this feature to make it compatible with the previous thumbor version that I used in my projects. It works for me, but of course it will be much more stable with tests. Thank you for your efforts, I hope it will be a useful feature.