Enable storing multiple compiled patterns at once

[ghost]

Hello,

Firstly, thank you for generously publishing this code in the public domain.

Here are changes which resolve #3, which also change the public API. In summary, we now have:

typedef regex_t re_t[MAX_REGEXP_OBJECTS];
int re_compile(re_t re_compiled, const char* pattern);

Here is a snippet which demonstrates the new functionality:
https://gist.github.com/jmher/95bbc3b286bf5eb40fee304e95c7ddc6

JM