modify public API header file in a way that it can be used without using a single TLR or rcX related header file

The public API headers

• PNSIF_API.h
• PNIO_spec.h
  shall be modified in such a way that a host application is able to use these header files without the need for any TLR or rcX header file.

To achieve this goal at least the following steps need to be done

• replace all TLR-datatypes with stdint datatypes (e.g. replace TLR_UINT32 with uint32_t)
• create a new header file PNSIF_osal.h which defines e.g. packed-macros and TLR-packet-header and TLR_EMPTY_PACKET and RCX_REGISTER_APP
• in PNSIF_API.h check if "TLR-packet-header" is defined. If not include the new header PNSIF_osal.h"