Corth - Better memory access

New load/store keywords

• loadb/storeb - byte
• loadw/storew - word (2 bytes)
• loadd/stored - double word (4 bytes)
• loadq/storeq - quad word (8 bytes)

Be sure to correctly offset memory address when manipulating values larger than a byte.
i.e. mem 0 + 65535 storeq will write memory from mem 0 + to mem 7 +.