new feature: mechanism to perform file and directory permission normalization within /rawdata

[georgemarselis-nvi]

All files under /rawdata should be 644 and directories should be 755 . that way we prevent random executables within the raw data.

this should be done in some other way, other than the half-hour script running os.chmod() itself.

pushing this down when this is daemonized and fork()ing for the responsible user.