update read me
string comparison
JhackOS: Array
JhackOS Array: memcpy
JhackOS: String.copy
JhackOS StringList
Jhasm: generate output filename
move Jhasm to toplevel
reorganize JhackOS
import chapter 6 tests
JhackOS String: indexOf substring
Jhasm: strip comments
JhackOS String: span/rspan
JhackOS String: lstrip/rstrip
Jhasm: strip whitespace
add whitespace to assembler test input
JhackOS String: subString
Jhasm: parse labels
JhackOS: rename StringList to ArrayList
Jhasm: symbol table