abundance-dist.py incorrectly not supporting output to STDOUT

[mr-c]

(env)mcrusoe@athyra:~/papers/2013-read-aligner/ecoli_rand_error$ abundance-dist.py reads.ht reads.fasta /dev/stdout | awk '{ print $2 }' 

|| This is the script 'abundance-dist.py' in khmer.
|| You are running khmer version 1.2-rc1-71-ged65dbc
|| You are also using screed version 0.7
||
|| If you use this script in a publication, please cite EACH of the following:
||
||   * MR Crusoe et al., 2014. doi: 10.6084/m9.figshare.979190
||   * Q Zhang et al., arXiv:1309.2975 [q-bio.GN]
||
|| Please see http://khmer.readthedocs.org/en/latest/citations.html for details.

ERROR: /dev/stdout exists; not squashing.
from
30
sizes:
to

Probably also abundance-dist-single.py. Squashing code should be updated to ignore /dev

[mr-c]

Diagnostic and status information is output to STDOUT instead of STDERR, which also defeats attempts to stream abundance information to another program.

[b-wyss]

I'll work on this one.

[mr-c]

This was done in #626