Initial implementation of custom commands feature (e.g. telnet).
Added .gitignore file.
Implemented preset support for custom commands.
Added command file for changing frequencies for Seowon devices.
Timeout handling for seowon_frequencies custom command.
Do not store available custom commands in device doc, find them from config. No longer having to reinitialize the device after adding a custom command.
Added task status code to force saving task. Used in addObject task to avoid data inconsistency and crashing.
Fixed possible bug caused by not clearing task cache when saving.
Return error instead of throwing exception when saving task.
Fixed saving task in addObject. Should be saved after receiving instance number rather than before.
Increase telnet timeout for seowon frequencies command.
Merge branch 'customcommands'