improved configuration of positional n-grams and their shift
make use of CONFIG_TYPE_BOOL and introduce program switches as
replacement for program arguments expecting 0 & 1 as value.
correctly handle old config files
correctly overwrite values of wrong type
merged bool_args code from master
fixed docs
position is 32bit signed int
simple rehash function
fixes to header file
merged in new configuration setup
some badly needed code beautification
merge from master