Feature request - add burn for airgrabbed tokens

[indykpol]

To free up the RAM occupied by test airgrabbed tokens (such as POOR) or airgrabbed tokens that an EOS user got rid of, please add an option to issue a burn contract (as described: https://github.com/generEOS/poorman.token#to-burn-tokens-run-the-command).

[indykpol]

This problem becomes more pertinent now that some of the creators of the airgrabbed tokens are using users own CPU to distribute spam on EOS:

Despite not performing any own transactions for a week, an account with 1 EOS staked for CPU has been depleted of all CPU resources:

This should be also explained when airgrabbing the tokens that a risk like that exists.