Allow user-specified output widths

[craigthomas]

Currently, the assembler prints out lines that are greater than 120 characters wide when using the --print or --symbols switches. Historically, console windows have been limited to 80 or 100 characters wide when initialized, unless users specify an override. In order for the output of the assembler to be more readable, the output width should be truncated to a reasonable size - approximately 100 or 120 characters. Additionally, a switch should allow for users to specify how wide they want the output to be when printing to the screen.