#236 Uninformative error message on file not found.

[William S Noble]

When assign-confidence is given as input the name of a file that does not exist, it prints the following error:

crux assign-confidence foo
INFO: Beginning assign-confidence.
WARNING: The output directory 'crux-output' already exists.
Existing files will not be overwritten.
INFO: CPU: pyrrolysine.gs.washington.edu
INFO: Tue Feb 3 13:16:31 PST 2015
FATAL: No search paths found!

The error message should instead read something like:

FATAL: The file "foo" does not exist.

[Jared Moore]

This seems to be fixed:
"Jareds-MacBook-Pro-2:crux-trunk Jared$ crux assign-confidence bla.txt
INFO: Beginning assign-confidence.
INFO: Writing results to output directory 'crux-output'.
INFO: CPU: Jareds-MacBook-Pro-2.local
INFO: Sun Oct 18 16:19:06 PDT 2015
FATAL: Target file bla.txt not found"