Rename additional to followup
Rename how samples are referred to

validation => followup
d0_tumor => discovery_tumor
d30_tumor => followup_tumor
d0_normal => normal
Mixed up discovery and followup
Rename method
Remove unused plan files
Use blank placeholder files

The Trio.t test does not actually compare the content of the output
files, only the existance.  By using blank files, we stop providing
the false impression that the test verifies the content of the files,
and we make the test easier to maintain.
Remove confusing d30 variable name
Merge pull request #85 from apregier/rename_trio_samples

Rename trio samples