Hazard Detection Unit and Forwarding Unit in processer added (started)

Still not completely added!
Hazard and Fowarding Units included

Minor changes has to be made see IDEX_opcode
Stall implemented not tested yet

Stall has been implemented but there are still problems for the ID/EX
register. Seems like .opcode[25 downto 21] is not used. But is actually
used for forwarding unit.
Forwarding mostly tested

- Stall not tested yet
- Forwarding with lw and sw not tested yet
See todo list in pipeline mips folder
TODO edited
Forwading unit modified Branch calc changed

The forwarding unit was modified so that it also forwards results for a
following sw. The branch calculation has been moved to the ID stage so
that the branch penalty when a branch was mispredicted is reduced.
Forwarding added, stall after lw added

- Forwarding for branch condition calculation added
- Stall insertion after lw added (instruction is now saved in IF/ID
register)
- PC is now updated on falling edge -> see problems.txt
Merge remote-tracking branch 'origin/Hazard-and-Forwarding'