Refactor Source#search_by_name to make use of Array#grep and use less te...

...mporary Strings. Add regular expression search.

This is a small rewrite to part of

pod search <query>

which makes it possible to use regular expressions.

It also slightly lowers memory usage, because it avoids using temporary strings. Instead, it uses an Array of existing strings and greps over them.

I've added only a single spec which shows off the capability. Please let me know if you need more examples.