Updated IDManager

ID member m_flags has been replaced with m_type, which stores the type
of the object referenced by the ID and added std::set<IDType> to the ID
manager to group relevant IDs in order to use them later in some
lv2/sys_process functions and the Kernel Explorer.
Kernel Explorer implemented
Minor sys_prx update
Linux compilation fixes
Merge pull request #766 from DHrpcs3/prx_loader

Kernel Explorer implemented