New TGeoParallelWorld class supporting navigation in a parallel flat node. Currently the parallel world is made by TGeoPhysicalNode objects which has to match paths in the active geometry. Coupling navigation via TGeoManager::SetSetUseParallelWorldNav(true) will prioritize the parallel world objects with respect to the ones in the real geometry.

(cherry picked from commit 2a7c470af52e9bf931f20cc27fe8ea1e280b0bfe)
Fixes for the new parallel world navigation feature with a tutorial macro

(cherry picked from commit 2c7ca5526c5bbf40951dd40da6dc88af118dfbd6)
roota must contain all of libRoot.a and export all symbols.
Do not include pq2 in libROOT.a - and especially not its main().
Do not load the lib for a class if its dictionary is available.

Thsi prevents AutoLoad() of libraries that are statically linked.
Detect a static build, initialize TCling from process image instead of libCling.

libRoot.a now contains a symbol (usedToIdentifyStaticRoot() from
core/base/src/roota.cxx) that the regular build does not have. It is used to
initialize TCLing from the binary instead of dlopening libCling, just like in
the rootcling case.
Fix make static for ROOT 6.
Add option for detailed output which is saved in result file
Remove redundant portion of code generated for dictionaries

as now the protoclasses carry the information.
Since we do not persist the ast in form of pcms (clang pcms), we
were obliged to transfer some annotations of the decls present
at dictionary generation time in the AST to the AST at runtime
(and of course, ultimately TClass) using c++ code in the
dictionaries.
Now, with ROOT pcms and protoclasses, the information is passed w/o
the need of these constructions.
Clean the code for treating insertion of entries in kForwardDeclared state

thanks to Philippe for the suggestions.
Pass the correct parameter to GenerateTClass
Note that ResolveTypedef can lead to autoloading and autoparsing
Return success in AutoLoad if dictionary is already loaded
Fix issues pointed out in http://root.cern.ch/phpBB3/viewtopic.php?f=3&t=18299

respect conventions of the example and do not port to ROOT coding
conventions the whole code.
TProtoClass::FillTClass: get mother classes before starting to fill TClass
White space
Create a 'forward declared' TClass for unknown base class
Silence warning
Enable header parsing on demand

set to true in the TCling constructor the boolean flag which was
previously steered by the HEADER_PARSING_ON_DEMAND env variable.
Fix doc macro: declare before use, and correctly so (return type) (ROOT-6448).