1.2.0: MODE_FILE fix when reader is loaded before forking

• Previously if MODE_FILE was used and the database was loaded before
  forking, the parent and children would use the same file table entry without
  locking causing errors reading the database due to the offset being changed
  by other processes. In MODE_FILE, the reader will now use os.pread
  when available and a lock when os.pread is not available (e.g., Python
  2). If you are using MODE_FILE on a Python without os.pread, it is
  recommended that you open the database after forking to reduce resource
  contention.
• The Metadata class now overloads __repr__ to provide a useful
  representation of the contents when debugging.
• An InvalidDatabaseError will now be thrown if the data type read from
  the database is invalid. Previously a KeyError was thrown.

1.1.1: Python 3 MODE_AUTO fix

• On Python 3 there was a potential issue where open_database with
  MODE_AUTO would try to use the C extension when it was not available.
  This could cause the function to fail rather than falling back to a pure
  Python mode.

1.1.0: Memory and file more for Python reader

• The pure Python reader now supports an optional file and memory mode in
  addition to the existing memory-map mode. If your Python does not provide
  the mmap module, the file mode will be used by default.
• The preferred method for opening a database is now the open_database
  function in maxminddb. This function now takes an optional read
  mode.
• The C extension no longer creates its own InvalidDatabaseError class
  and instead uses the one defined in maxminddb.errors.

1.0.0

• First production release.
• Two potential C extension issues discovered by Coverity were fixed:
  • There was a small resource leak that occurred when the system ran out of
    memory.
  • There was a theoretical null pointer issue that would occur only if
    libmaxminddb returned invalid data.

0.3.3

• Corrected initialization of objects in C extension and made the objects
  behave more similarly to their pure Python counterparts.

0.3.2

• Switched to Apache 2.0 license.
• We now open the database file in read-only mode.
• Minor code clean-up.

0.3.1

• Fixed packaging problem that caused import to fail.

0.3.0 Added pure Python implementation

• This release includes a pure Python implementation of the database reader.
  If libmaxminddb is not available or there are compilation issues, the
  module will fall-back to the pure Python implementation.
• Minor changes were made to the exceptions of the C extension make them
  consistent with the pure Python implementation.

0.2.1

• Removed -Werror compiler flag as it was causing problems for some OS X
  users.

Cleaned up code

• Refactored code and fixed a memory leak when throwing an exception.