added sdram address decoding

cMIPS/bin/edMemory.sh

cMIPS/include/cMIPS.h

cMIPS/include/cMIPS.ld

cMIPS/include/cMIPS.s

cMIPS/tests/sdram1.s

cMIPS/vhdl/core.vhd

cMIPS/vhdl/packageMemory.vhd

cMIPS/vhdl/sdram.vhd

cMIPS/vhdl/tb_cMIPS.vhd