MacroRootDict. Improving the identification of structures for dictionary generation

[jgalan]

See also the following closed PR: #356

There was a problem with c++ structure identification for dictionary generation. The cmake macro identifying the struct keyword was also identifying the keyword structure that appears on the documentation.

• A quick fix is added in this PR to search for the struct keyword with an additional space behind.

This PR solves the proper streaming of TRestRawBiPoToSignalProcess that was not properly storing MatacqBoard information.

However, there is an additional problem the cmake macro was only identifying the first struct found in the class.

• The macro has been updated so that multiple structures can be added to the dictionary. The resulting LinkDef file is then auto-generated as follows (for the case of TRestRawBiPoToSignalProcess). Now both structures, MatacqBoard and BiPoSettings appear on the LinkDef file.

#ifdef __ROOTCLING__
#pragma link off all globals;
#pragma link off all classes;
#pragma link off all functions;
#pragma link C++ nestedclasses;
#pragma link C++ nestedtypedef;
#pragma link C++ class MatacqBoard+;
#pragma link C++ class std::vector<MatacqBoard>+;
#pragma link C++ class BiPoSettings+;
#pragma link C++ class std::vector<BiPoSettings>+;
#pragma link C++ class TRestRawBiPoToSignalProcess+;

The following PR will require the updates introduced in this PR.

rest-for-physics/rawlib#106