Efficient arrays of booleans -- C extension.

This module provides an object type which efficiently represents an
array of booleans. Bitarrays are sequence types and behave very much
like usual lists. Eight bits are represented by one byte in a
contiguous block of memory. The user can select between two
representations; little-endian and big-endian. All of the
functionality is implemented in C. Methods for accessing the machine
representation are provided. This can be useful when bit level access
to binary files is required, such as portable bitmap image files
(.pbm). Also, when dealing with compressed data which uses variable
bit length encoding, you may find this module useful.
