whitelist/blacklist docs/var names seem to be wrong

[thehesiod]

per settings.py:
# If provided, a regex string that matches execution paths (read: not files),

this ends up going to santa via santa_const.PREFLIGHT.WHITELIST_REGEX, and the docs in santa say:
A regex to whitelist if the binary or certificate scopes did not allow execution. Regexes are specified in ICU format.

and the examples I see say this doesn't have to be a directory.

[thehesiod]

also, comments should be added stating that the effects of the values will not be reflected in the blockable state until #30 is fixed