Make TrajectorySmoothers const thread-safe

Most of the TrajectorySmoothers were changing the direction of their
Propagators in a const function. That is not thread safe. To fix the
problem the TrajectorySmoothers now hold two Propagators which only
differ based on their propagation direction.
enable MT pattern reco in cosmic sequence
bugfixes and restoring backwards copmatibility of Combinatorial pattern recognition algo in DT
updated magnetic field and generator for Geant4 10
Make mutable in EventSetupRecord atomic

The transient access bool is now atomic since multiple threads could attempt to change it.
Merge pull request #3709 from jpavel/71x_taus_dZVxmatch

Reco -- Changing the vertex matching algorithm for taus
Made static const in ExpressionVar
Merge pull request #3601 from cms-btv-pog/UpdatedJetFlavourStorage_from-CMSSW_7_1_X_2014-04-29-0200

Updated storage of flavor information in pat::Jet
add a few consts
Merge pull request #3729 from davidlange6/140507_fix_datamixing_compilation

add a few consts
multithreaded DQM
multithreaded DQM
multithreaded DQM
multithreaded DQM
multithreaded DQM
multithreaded DQM
multithreaded DQM
multithreaded DQM
multithreaded DQM
multithreaded DQM