Add support for returning more detailed information in the case of a
swap failure in the xmlrpc server. To use it, the extra option "extrainfo" needs to be set to true. This will cause "value" to be a structure (in the XML-RPC sence) with useful information instead of just the exit value of the script. The structure will contain at least the following fields: cause: "temp", "user", etc cause_desc mesg: more specific error information exitval: script return value log: activity log Note, that value may still be an integer in the case of some other failure that is not swap related. To support this, the "-X" option was added to swapexp and batchexp which will output a RPC-XML method response to stdout when possible.