Proof of concept - comment system

Hello,

after reading a twitter question about a getKirby based comment system i put together some lines of code.
Maybe it is helpfull for somebody.

I put the code into a gist at: https://gist.github.com/svnt/9ef24a0be14d5208fdad

I would appreciate some comments especially about input/output sanitizing and spam protection.

best regards,
Svnt