Don't use MustCompile() for dynamically built regexes

[Gustavo Kristic]

This is a follow up on #15. The use of MustCompile() for a regular expression can easily crash an application. I suggest using Compile() instead and handling the error appropriately.

[Preetam]

There's work to remove regular expressions completely: #14

[Gustavo Kristic]

Okay. If that's ongoing work then this issue makes no sense. Closing!