setup stepper fail map (for force scanning i.e. number of trials before succeding).
modified:   Makefile: upgarde version to v0.2.8 .
modified:   VERSION: version v0.2.8 .
modified:   scan.h: setup increment of data4scan fail map in scanning_force function only.
modified:   scan.help.output: automatic update.
merge in progress
modified:   scan.cpp: add usage line from master branch.
modified:   scan.help.output: master one for merging.
Merge branch 'dev_scan_class'

Conflicts:
	scan.help.output