CmdThread do not catch and forward exceptions to the main thread

Many camera plugins use CmdThread to make commands that take a long time asynchronous.

Commands (see execCmd) are executed in cmdLoop() but there is no try catch block to handle exceptions, which means that the loop (and then thread) is exited when an exception if thrown from a command. The plugin is then in dangling state, unable to execute any commands and a restart is required.

A possible implementation would be to catch and store the exception in the cmdLoop() and pop and rethrow it in the next call to waitStatus() / waitNotStatus().

Most calls to sendCmd are followed by waitStatus() / waitNotStatus().