Add active learning test - test #24
add reference stdout+stderr for test #24
allow undefined-> (assume empty) stdout reference
No need for stdout ref for test #24
deleted test/train-sets/ref/active-simulation.t24.stdout (empty files no longer needed)
Forgot to include this:  demo/random-noise/distrib.r
Merge branch 'master' of git://github.com/JohnLangford/vowpal_wabbit
Refresh test/train-sets/ref/0002.stderr to have 6-digit precision
modified:   test/train-sets/ref/0002.stderr (missing examples/pass & passes)
modified: test/train-sets/ref/active-simulation.t24.stderr (add per pass + passes used)
Merge pull request #151 from hal3/master

Done.
Merge branch 'master' of git://github.com/JohnLangford/vowpal_wabbit
vw-varinfo: Fix bug found by Alina: --feature_mask not recognized as preceding filename
fix loss accounting bug
fixed some loss accounting
Merge pull request #149 from arielf/master

Add test for recent active-learning regression
fixed active learning bug, I believe
test check
cosmetic fix: warning message and comment
unused var