Replace "public domain" with a license in scripts

[sidkshatriya]

While looking at the script /bin/chimera-prunekernels (See #38 ) I noticed the following statement at the script header:

# I (q66 <q66@...org>) hereby place this script in the public domain.

I am not a lawyer -- but would it be better if we just released this (and any other scripts/code) which are in the "public domain" to some specific license (BSD, MIT etc.) ? This is because "public domain" could mean different things in different countries. Giving a specific license just makes things clearer to the future contributors and users about rights/responsibilities related to code in question. And if the code is released under some liberal license there should be minimal practical difference vs "public domain", right ?