Document extra dependencies
Use only spaces for indentation

Python 3 does not like mixing tabs and spaces.
Clean up dead, redundant, and unused code

* Unused parameters, methods and attributes
* Redundant strip() calls extracting names and values from “options”
* “pos” is always 0 or -1, which is less than or equal to the length of any
  string
* Content decoding seems to be done with internal wrappers around the parsers
* No point checking again for newline in HTTP client after verifying a
  newline was added to the buffer
* stat() result index 9 is actually ST_CTIME; but it appears “mtime” was
  actually intended
* Can’t get past parse_image_jpeg.__init__() without setting “tfname”
* __getattr__() normally passed a single attribute name without any full
  stops (.)
“BookmarksParser” module doesn’t seem to be used
Eliminate duplication between “cookielib” and “ht_time” modules
Reader.LoginDialog unused and appears to duplicate the Authenticate module