Merge pull request #1 from srjek/assembler-dev

Promote dev branch
Avoid printing error messages many times over during the optimize step. Instead print once in build, if still applicable.

Signed-off-by: Josh Kilmer <srjek2@gmail.com>
Values of dcpu16 instructions also avoid reporting errors during optimize()

Signed-off-by: Josh Kilmer <srjek2@gmail.com>