Migration to multithread friendly modules

[mbluj]

In this pull request modules used by HLT paths with taus are migrated to multithread friendly modules - in most to edm::global::EDProducer.
In addition const data members of many of the modules explicitely defined as const.
The pull request should be also forwardported to 74X release series.

[cmsbuild]

A new Pull Request was created by @mbluj for CMSSW_7_3_X.

Migration to multithread friendly modules

It involves the following packages:

HLTrigger/btau
RecoTauTag/HLTProducers
RecoTauTag/TauTagTools

@perrotta, @cmsbuild, @nclopezo, @fwyzard, @Martin-Grunewald, @StoyanStoynev, @slava77 can you please review it and eventually sign? Thanks.
@ferencek, @acaudron, @jpavel, @pvmulder, @imarches this is something you requested to watch as well.
You can sign-off by replying to this message having '+1' in the first line of your reply.
You can reject by replying to this message having '-1' in the first line of your reply.
@nclopezo you are the release manager for this.
You can merge this pull request by typing 'merge' in the first line of your comment.

[slava77]

+1

for #6686 d15891c

based on tests in for #6687 8a8b639
which is identical to this

[slava77]

+1

for #6686 1914235
based on jenkins tests (no differences observed)

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_7_3_X IBs unless changes (tests are also fine). This pull request requires discussion in the ORP meeting before it's merged. @davidlange6, @nclopezo, @ktf, @smuzaffar

[davidlange6]

+1