add flash user page and validate

some program hex files contain data in the user page section.  this
is the case if code intefaces with data contained in this page.
functionality added :
 check if data in hex file resides in user page region
 if so:
    flash this data along with program
    validate this data along with program validation

also - moved 'buffer' initialization inside validation check.
buffer does not need to be created if validation is suppressed,
so no reason to possibly get an error allocating memory if buffer
will not be used.