updated dns to support regex + fixed loop + fixed assumptions

[eyJhb]

Initially I couldn't get tinydns to run at all, which was fixed in the commit below.
As well as added support for using regex for domains, which could maybe be enabled/disabled (for usecases where it's not needed).
Besides this, some assumptions was made about the structure of the question packet, which was not always true, ie. when using dig it would send additional information, which this library did not handle well.
Now it parses the response one byte at a time,instead of reading at the end.

Things that should be fixed

• Make flag to enable/disable regex
• enable/disable regex should use simple compare, and maybe use the previous implementation to use less memory
• Remove last . in domain