Protocol string is set has const char in fko_protocol_t.
New tests for rc file processing (SPA_SOURCE_PORT, FW_TIMEOUT).

Added spa source port variable to dump_transmit_options() and renamed port
to destination port.
Removed duplicate variable in the test suite (fake_spoof_ip/spoof_ip).
First attempt to not ovewrite some configuration variables with --save-rc-stanza.

At this time it only does not overwrite the KEY and HMAC variable without asking the user
what he wants to do.
Continued implementing a way to not overwrite KEY.. variables with --save-rc-stanza
mrash/fwknop#67
Fixed names of function for better understanding.
Merge remote-tracking branch 'upstream/master'
Ask the user whether he wants to overwrite a variable in the updated rc file or not.
Added --force-stanza command line arg to avoid prompting the user.
Added GPG_SIGNER and GPG_RECIPIENT to the list of important variables.
Merge remote-tracking branch 'upstream/master'
Added force-stanza to the client documentation.
Fixed command line arguments (key-base64-rijndael and key-base64-hmac).

The cmd_opts structure containing the command line args does not follow the
documentation. This update fix it.
Replaced printf() by log_msg().
Added new tests to the test suite to validate the --save-rc-stanza command line argument.
Merge remote-tracking branch 'upstream/master'