CRAN release 0.8.0

• mirai 0.8.0 is a major feature release. Special thanks to @wlandau for suggestions, discussion and testing for many of the new capabilities.
• Compute profiles have been introduced through a new .compute argument in daemons() and mirai() for sending tasks with heterogeneous compute requirements.
  • daemons() can create new profiles to connect to different resources e.g. servers with GPU, accelerators etc.
  • mirai() tasks can be sent using a specific compute profile.
• daemons() interface has a new url argument along with dispatcher for using a background dispatcher process to ensure optimal FIFO task scheduling (now the default).
  • Supplying a client URL with a zero port number :0 will automatically assign a free ephemeral port, with the actual port number subsequently reported by daemons().
  • Calling with no arguments now provides an improved view of the current number of connections / daemons (URL, online and busy status, tasks assigned and completed, instance), replacing the previous daemons("view") functionality.
• dispatcher() is implemented as a new function for the dispatcher.
• server() gains the following arguments:
  • asyncdial to specify how the server dials into the client.
  • maxtasks for specifying a maximum number of tasks before exiting.
  • idletime for specifying an idle time, since completion of the last task before exiting.
  • walltime for specifying a soft walltime before exiting.
  • timerstart for specifying a minimum number of task completions before starting timers.
• Invalid URLs provided to daemons() and server() now error and return immediately instead of potentially causing a hang.
• eval_mirai() is removed as an alias for mirai().
• 'mirai' processes are no longer launched in Rscript sessions with the --vanilla argument to enable site / user profile and environment files to be read.
• Requires nanonext >= 0.8.0.
• Internal performance enhancements.