Pass OBJECT_DIR to make (dev) plugin-loading easier
Cleanup
Added PD_EXPORT + some cleanup
Use PD_EXPORT to export InitPlugin
Split ProDBGAPI into different files

* This is because we need PDBackend and PDView plugin types (and maybe
more in the future) and it makes more sense to split these into
different files
Use string for type
Fixed memory leak and send in correct plugin type
Use string for plugin type
Added start of RegistersView plugin