Fix Coverity reports

G__ci.h: #11161 missing initialization
common.h: #11161 missing initialization
error.cxx: #20793 Array compared against 0
init.cxx: #11712 explicit null derefence
macro.cxx: #10192 missing initialization
shl.cxx: #10626,10627 constant expression result

TBranchProxy.h: #10047 unchecked return value
TTreeProxyGenerator.cxx: #10059,#10060 enum as boolean
TClassEdit.cxx: #11546,#11734 forward null pointer
TStreamerInfoWriteBuffer.cxx: #11572, #11573 forward null pointer
TTreeFormula.cxx: #11587,#11588,#11592 forward null pointer
   #11618,#11619 unckecked dynamic cast
TTreePlayer.cxx:  #11984,#11985,#11986 dereference after null check
TTreeIndex.cxx: #11596  unckecked dynamic cast
TChainIndex.cxx: #11597,#11988 unckecked dynamic cast
TOracleServer.cxx: #11898 dereference after null check
TH1.cxx: #11983 dereference after null check
TFileDrawMap.cxx: $10896 copy into fixed size buffer


git-svn-id: http://root.cern.ch/svn/root/trunk@35344 27541ba8-7e3a-0410-8455-c3a389f83636