mod_base: Add 'filter_not' filter for inversely filtering a list
doc: Add documentation for 'filter_not' filter
mod_base: rename 'filter_not' filter to 'reject'
doc: Update documentation on 'reject' filter
mod_base: rename 'reject' filter to 'exclude'
docs: Update documentation on 'exclude' filter
Merge pull request #768 from mawuli-ypa/filter-not

Add exclude filter for inversely filtering a list.