program code: changed to use standard vector

moved program word and code classes to new header file
made code vector member instead of base class
added necessary code vector pass through access functions
used vector functions instead of raw memory move function
added instruction and operand program word constructors for emplace back
modified program model functions to use iterator instead of pointer
modified program model encode to use emplace back to build program line
added new header to cmake since there is no corresponding source file
(only needed to make header show up in QtCreator project file list)