refs #1110: added C++ layer to store common/shared table arrays in a std::map
 * Sharing tables is only active if ModelicaStandardTables.c is compiled as C++ (flag -x c++ for GCC or /TP for Visual C++) and {{{NO_FILE_SYSTEM}}} is not defined
 * Write access to static variables is guarded by a critical section (Windows) or POSIX thread mutex (Linux)
 * Update (re-read) of the shared tables is not implemented (as it is certainly not required)

git-svn-id: https://svn.modelica.org/projects/Modelica/trunk@6772 7ce873d0-865f-4ce7-a662-4bb36ea78beb