[Disco_F429ZI] extensions of interrupt vectors, pin names and pin functions

Added some missing F429 interrupt vectors, pin functions, port and pin names.

The basis of the target was DISCO_F407. 
The STM32F429 has some additional pin functions which are added with these commits. Also all port names, pin names and pin functions of the larger packages are added not only the available ones of the F429ZI package. 
The mcu name in linker script and startup file is changed to 429.
Thanks for explaining. I understand it now, and would propose to have that explanation there on top (why are those lines commented out).