Improve error handling for internal nodes
Add option to correct lengths in tree building
Refactor tree analyses
Improve help for treeviz
Bump version to 0.1.1
Fix option to correct lengths
Silence much analysis terminal output
Output lineage classification with new TAB file

I added a function in the analysis of the tree which outputs a TAB file
that captures distant lineage classification.
Correlate analyzed trees to output TAB file
Allow multiple TAB files to be used

This includes a sloppy hard-coded change to header rev 1.
Attempt to add bigfile support to treeviz

Specifically, I hope to be able to handle big TAB files.
This commit is an intermediate stage, that does not test well.
Accumulate TAB entries from all specified TAB files

This fixes the problem that the list of TAB entries was being reset upon
reading each new TAB file, so that the only TAB entries that would be in
memory would be those from the last one specified.
I also made a minor fix to the documentation.
Make branch collapsing robust to nameless nodes

Apparently there were some trees that had nodes with no names, rather
than name == 'NoName', so I added that as a condition for collapsing
branches to avoid throwing exceptions.
Add a command line argument to specify header rev

It uses some global variables, but I think that this is an appropriate
use.