tools in src/ should not use libopts for parsing cmd line options

The tools in src/ use libopts to parse the command line options and as we are disentangling from it, certtool should use something simpler.

• certtool
• psktool
• srptool
• p11tool
• tpmtool
• systemkey-tool
• gnutls-cli
• gnutls-cli-debug
• gnutls-serv