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.

This version has a major fix regarding merging of VIIRS data. Do not use
any previous version for VIIRS merges.

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

Except for the draconian line length limit (used
--max-line-length=99).

* Don't require same file type for all files.
* Fix bugs in packet handling.
* Properly close files to avoid exhausting file descriptors for large
  numbers of RNSCA flies.

Conflicts:
	setup.py