Provide different error message for DAS lookup issues.

[ktf]

Fix the longstanding bug where a das failure is indicated as an error in
step two. This introduces a new DAS_ERROR exit code which is correctly
associated to step1. This is still not enough to catch the cases in
which is the lookup for pileup which fails, but at least is a good
start.

[cmsbuild]

A new Pull Request was created by @ktf (Giulio Eulisse) for CMSSW_7_4_X.

Provide different error message for DAS lookup issues.

It involves the following packages:

Configuration/PyReleaseValidation

@cmsbuild, @srimanob, @nclopezo, @boudoul, @franzoni can you please review it and eventually sign? Thanks.
@ghellwig this is something you requested to watch as well.
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[ktf]

@nclopezo this probably requires cleanups also in the way we process logs. In particular we should have a different color (puke green?) for DAS errors.

[ktf]

shocking pink is good as well..

[cmsbuild]

+1
Tested at: 8751bc9
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-6641/1194/summary.html

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-6641/1194/summary.html

[nclopezo]

I added the label for the "DAS_ERROR" in this pull request: cms-sw/cms-sw.github.io#11

[ktf]

Discussing privately with @franzoni we agreed this is a nice thing to have (Gio' correct me if I'm wrong). Bypassing pdmv signature.

[franzoni]

haven't had the time to look at it - but yes, the described functionality is good to have.