Fixed an inifite loop in the lexer.

If the last line of a file was blank it would keep trying to find a
non-blank line. It now checks to ensure the stream isn't at the end.
Fixed assemble() which wasn't incremnet the location counter when an
instruction was read.

This accidently got lost when git was refusing to let me unstage the line
when I was trying to commit another change first.
Added first DLX source file - Problem 1 for Project Euler.

Up until now, I had been testing the assembler using my solutions to
practicals (assignments) set by the University of Adelaide which I don't
to make public. Otherwise, if they re-use the assignments someone may
find the solution.
Added .gitignore - Ignores the build folder.

Additionally ignores .jar and .dlx files.
Added waf and waf script to build dasm.

Up until this point, I had been manually typing in the command line for
cl (Microsoft C++ compiler) and re-executing it each time.