changes

Added debug option(set the global debugmode to 1, prints extra info)
code cleanup (removing unused variables, and completely unnessary code)
refactoring write code into a function (untested, and not used yet)
refactoring read code into a function (untested, and not used yet)
renames some variables as to not be "protected globals" as the ide called it.
moved the 0 frame to a global, potentially for a new check to compare with correct header (also untested)
Improved spelling and description of some errors
added additional option (force) to continue on connection error
added additional option testframe (t) reads frame and prints raw hex data.