Squashed commit of the following:

commit 76ad8de8
Author: Bruce Flynn <brucef@ssec.wisc.edu>
Date:   Thu May 6 15:37:10 2021 -0500

    test, then push

commit e3a51b48
Author: Bruce Flynn <brucef@ssec.wisc.edu>
Date:   Thu May 6 15:31:48 2021 -0500

    rdrgen Fix attr comparison issues, support additional mission names

commit bb6b5e6d
Author: Bruce Flynn <brucef@ssec.wisc.edu>
Date:   Thu May 6 14:11:49 2021 -0500

    modis merging working and tested

commit 58143956
Author: Bruce Flynn <brucef@ssec.wisc.edu>
Date:   Wed May 5 13:13:23 2021 -0500

    fix bad attr

commit f3bdd86d
Author: Bruce Flynn <brucef@ssec.wisc.edu>
Date:   Wed May 5 11:21:20 2021 -0500

    add module for EOS utils

commit b18d65bb
Author: Bruce Flynn <brucef@ssec.wisc.edu>
Date:   Wed May 5 11:20:59 2021 -0500

    merge: support aqua by using seqid in pointer

Using stamp could possibly cause issues due to UTC datetimes not being
aware of leap seconds.

corrupt session groups can have packet files with multiple APIDs
we handel this by filtering these out and skipping to the next stamp

Because merge was only considering stamp/apid packets for the same
stamp/apid with different byte size were being treated as equal. It now
always treats packets/group with more bytes as more gooder.

Add option to CLI tool to specify VIIRS APID order. **NOT TESTED

Replaced the merge code with something less efficient but easier to
grok.

New stream impl that does not read the data that will be used to create
and index used in new merge code.

* Ensure streams is a know iterable type (deque)
* Make sure to reuse a stream in the case of a bad packet group. This was
  done with an exception so it was handled the same way as the other 2
  major cases.

bug fix, we were doing streams.remove(stream) inside a "for stream in streams:" which gave incorrect results

Fixes issue #1.