Allow native port to link additional libs from app

Might come handy for e.g. testing frameworks

Conflicts:
	redbee-econotag/drivers/redbee_uart.c
	redbee-econotag/drivers/redbee_uart1.c

board_init.c:7:1: warning: 'static' is not at beginning of declaration
[-Wold-style-declaration]

german "intern" to english "internal"

split up drivers to avoid building unnecessary files

also made some minor changes to shared wsn430-common files

* fixed a missing variabl declaration in redbee_uart1.c

fixed old-style-declaration warning

rename kernel_intern.h

board_init.c:7:1: warning: 'static' is not at beginning of declaration
[-Wold-style-declaration]