Check behavior of DefineClones when JUNCTION is None

[Jason Vander Heiden]

Chris found a bug a long time ago, were 'None' was being interpreted as a valid junction of length 4. We need to see if this is still true, and fix it if that's the case. I think empty sequence fields end up as empty strings, but we should probably still handle the 'None' case for safety.

[Namita Gupta]

I believe this was Issue #34 and I resolved it awhile ago.

[Jason Vander Heiden]

Doh. It does look like a duplicate. Though, it doesn't appear to be fixed. I just ran a test with JUNCTION='None' and the sequence made it into the clone-pass file with the junction sequence 'NONE'.

[Jason Vander Heiden]

The best way to handle this might be either in Receptor.IgRecord or IO.readDbFile by ensuring that the string 'None' gets converted to the constant None.

[Namita Gupta]

Fixed this so sequence fields that are 'NA' or 'None' are converted to NoneType or '' when read in.