Queue improvements

[blattm]

Some improvements to the RoAMer-queue:

• use the --first flag to put samples at the front of the queue
• more than one sample/folder can be given to the CLI at once
• it is now possible to leave the monitoring of samples running after an Ctrl-C interrupt.
• the new --continue flag can be used to instruct the queue to ignore samples which already have a _dump folder. This option also works correctly in combination with --ident and --output

[danielplohmann]

awesome, thank you very much!