Revision 41862

   o PiecewiseInterpolation, RooAbsCachedReal, RooAbsCachedPdf

     - Follow adjustment in RooCacheManager


   o RooConvCoefVar, RooEffProd, RooResolutionModel, RooErrorVar, RooProjectedPdf, RooAbsHiddenReal

     - Migrate to getValV


   o RooProdPdf

     - Follow adjustment in RooCacheManager     
     - Migrate to getValV


   o RooVectorDataStore

     - Various small fixes

     - Allow storage of non-constant 'track-and-change' cache entries.
       These are cached PDF nodes that are not constant, but need
       to be recalculated when selected parameters change. A 
       RooChangeTracker data member is added to the vectors to
       do this dependency checking, and recalculation (as needed)
       is performed in method recalculateCache() to be called from
       the test stat before looping of the data.
       

   o RooAbsReal

     - Introduce new non-virtual inline getVal() methods that handles
       clean-cache state cases and delegates all other cases to a 
       virtual method getValV() that corresponds to the original
       getVal() method


     - Add 'ignore' more to eval error logging protocal


   o RooAddPdf

     - Follow adjustment in RooCacheManager 
     - Optimize control structure in evaluate() to be more efficient
       (move conditional outside loop)

   o RooAbsTestStatistic

     - Add extra argument to constOptimizeTestStatistic to control
       activation of track-and-change optimization

   o RooRealMPFE

     - Migrate to getValV()

     - Add support for new track-and-change option argument in 
       transmission of const optimization request to servers
       

   o RooRealVar

     - Exploit new _fast flag of RooAbsReal to choose non-virtual
       handling of getVal()

     - Migrate to getValV() [ but still dummy ]

     - Small fix in attachToVStore()


   o RooNLLVar

      - Add data member tracking first use

      - After first use, trigger wiring of all caches in RooCacheManagers
        to speed up trivial cache selection decisions (i.e those where
        only a single cache entry exists)

      - Add call to RooAbsDataStore::recalculateCache() to implement
        track-and-change update prior to likelihood loop


   o RooConstVar

      - Migrate to getValV()


   o RooAbsArg

     - Eliminate flipACLean() protocol since no longer used

     - Simplify method opermode() now that flipAClean is abandoned.

     - In findConstantNodes() add support for change tracking
       and include nodes with "ChangeTracking" atttribute in
       list of constants. Mark all truly constant expressions
       with attribute "ConstantExpression"

     - Add extra argument to constOptimizeTestStatistic to control
       activation of track-and-change optimization  

     - In printCompactTree() also print valueDirty state when in Auto mode


     - Add method wireAllCaches() which propagates cache wiring request
       to all registered cache nodes on all branches nodes

     - Add transient data member with namereg pointer to string with
       current object name. Overload SetName() and SetName() and title
       to clear pointer whenever name changes.


   o RooAbsPdf

     - Migrate to getValV(). Eliminate handling of clean-cache cases
       as this is now done in RooAbsReal::getVal()

     - Disable use of RooAbsPdf::raiseEvalError() protocol as this
       is now communicated through RooAbsReal::logEvalError()


   o RooRealIntegral

     - Migrate to getValV()

     - Use setInhibitDirty() instead of flipAClean() in evaluate()
       when performing numeric integrations


   o RooTreeDataStore

     - In cachArgs() add code to select only cache items with
       label "ConstantExpression" as tree store is unable to
       cache track-and-change items

   o RooAbsCategory

     - When printing also show index associated to label


   o RooAbsOptTestStatistic

     - Add extra argument to constOptimizeTestStatistic to control
       activation of track-and-change optimization

     - In optimizeConstantTerms() when trackChanges option is active
       request change tracking for all component nodes of RooAddPdf
       and RooRealSumPdf, unless these components are RooProdPdf/RooProducts
       respectively in which case the components of these products are tracked
       
   o RooRealProxy

     - Use _fast attribute of RooAbsArg to directly return value cache
       of RooAbsReals if that is allowed


   o RooAbsCache

     - Add virtual method wireCache()


   o RooCacheManager

     - Add new method getObj() that takes isetRangeName as 'const char*'
       instead of 'const TNamed *' to be able to eliminate the conversion
       when in wired mode

     - Implement cache wiring - If at moment of the request only a single
       cached entry exists - always return that one from here one.


   o RooAbsDataStore

     - Implement virtual method calculateCache()