get_priv: add option to modify privileges in thread token

[zer1t0]

Hi,

Recently I was in a situation where required to enable the permissions of an impersonated token, however get_priv only allows to modify the main token of the process, so I added an option to modify the thread token, which is the impersonated one.

For enabling privileges in process token the command remains the same, but in case you want to enable privileges in the thread token, you must prepend a ~ symbol in the name of the privilege.

For example, indicate "SeDebugPrivilege" will enable the debug privilege in process token and "~SeDebugPrivilege" will do it in the thread token.