Partly fix constness violations of RpcROD_Decoder

http://goetz.web.cern.ch/goetz/mutable_2019-07-13.html#Cnv_Muon

nightly/master/2019-07-13T2149:MuonSpectrometer/MuonCnv/MuonRPC_CnvTools/src/RpcROD_Decoder.h +128
6c73c628f9a81b45be732634dc8e621146297b26	2019-04-29_T1202	Adam Edward Barton	Rename IDC::tryFetch to tryAddFromCache
0572ff0c07d40189b3990a0d130cbae5fb9e184e	2019-04-03_T1745	scott snyder	MuonRPC_CnvTools: Fix clang warnings.
3b768443550c47f3d812b16601f09566e2609224	2019-03-19_T1412	Ian Connelly	Updating the for loops to use range based
6136df6a9338bf217096b5392c3f4b9f1406919d	2019-03-12_T1735	Ian Connelly	Using tryFetch method to query the container cache in order to allow a map of undecoded collections to be created
c73b607dae2d15f2d9085b21f6ecd5ba59f545dc	2019-03-08_T1643	Ian Connelly	WIP for debugging RPC changes
342deef2163cafe2da462e3f5584de9ad2cf29ba	2019-02-28_T1649	Ian Connelly	Adding update for cache container in one of the ROD decoders. Need to test with cache on, without cache, seems to run

   126	    //====LBTAG==== Added 02112008 for buffer format check
   127	    mutable int m_previous;
   128	    mutable int m_printerror;
   129	    mutable bool m_RPCcheckform[13];
   130	    mutable int  m_RPCcheckfail[13];

nightly/master/2019-07-13T2149:MuonSpectrometer/MuonCnv/MuonRPC_CnvTools/src/RpcROD_Decoder.h +130
6c73c628f9a81b45be732634dc8e621146297b26	2019-04-29_T1202	Adam Edward Barton	Rename IDC::tryFetch to tryAddFromCache
0572ff0c07d40189b3990a0d130cbae5fb9e184e	2019-04-03_T1745	scott snyder	MuonRPC_CnvTools: Fix clang warnings.
3b768443550c47f3d812b16601f09566e2609224	2019-03-19_T1412	Ian Connelly	Updating the for loops to use range based
6136df6a9338bf217096b5392c3f4b9f1406919d	2019-03-12_T1735	Ian Connelly	Using tryFetch method to query the container cache in order to allow a map of undecoded collections to be created
c73b607dae2d15f2d9085b21f6ecd5ba59f545dc	2019-03-08_T1643	Ian Connelly	WIP for debugging RPC changes
342deef2163cafe2da462e3f5584de9ad2cf29ba	2019-02-28_T1649	Ian Connelly	Adding update for cache container in one of the ROD decoders. Need to test with cache on, without cache, seems to run

   128	    mutable int m_printerror;
   129	    mutable bool m_RPCcheckform[13];
   130	    mutable int  m_RPCcheckfail[13];
   131	    IntegerProperty m_maxprinterror;
   132	    

nightly/master/2019-07-13T2149:MuonSpectrometer/MuonCnv/MuonRPC_CnvTools/src/RpcROD_Decoder.h +148
6c73c628f9a81b45be732634dc8e621146297b26	2019-04-29_T1202	Adam Edward Barton	Rename IDC::tryFetch to tryAddFromCache
0572ff0c07d40189b3990a0d130cbae5fb9e184e	2019-04-03_T1745	scott snyder	MuonRPC_CnvTools: Fix clang warnings.
3b768443550c47f3d812b16601f09566e2609224	2019-03-19_T1412	Ian Connelly	Updating the for loops to use range based
6136df6a9338bf217096b5392c3f4b9f1406919d	2019-03-12_T1735	Ian Connelly	Using tryFetch method to query the container cache in order to allow a map of undecoded collections to be created
c73b607dae2d15f2d9085b21f6ecd5ba59f545dc	2019-03-08_T1643	Ian Connelly	WIP for debugging RPC changes
342deef2163cafe2da462e3f5584de9ad2cf29ba	2019-02-28_T1649	Ian Connelly	Adding update for cache container in one of the ROD decoders. Need to test with cache on, without cache, seems to run

   146	    // flag to read old sector 13 data
   147	    BooleanProperty m_sector13Data;
   148	    // mutable MiniBenchInternals::Bench m_bench;
   149	
   150	    //RpcByteStreamErrorContainer *m_bsErrCont;

RunTier0Tests.py was fine. RunTier0Tests.log