Conditional assembly to reduce size of driver

[erangell]

For special purpose applications, the unnecessary parts of the driver can be excluded from assembly, and variables in the makefile can control what gets assembled. I would like the following:

ANNUNCIATOR= <0 to 3> - assemble just the addresses for the selected annunciator
NEGATIVELOGIC = 0 or 1 - set to 1 to include the code that handles negative logic, and enable it by default.
If either of the above parameters are undefined, assemble the current source code without modifications.