0.4.7: bugfixes and enhancements

• bugfix: stall on some kinds of error in recv(), PR #56
• bugfix: sequence number miscalculation in send(), PR #52
• enhancement: callback function added for recv() method, PR #53
• bugfix: receiving empty file and stall condition in recv(), PR #50
• bugfix: callback is now called for some kinds of errors and some CLI fixes, 8a798e8
• bugfix: remove DepreactionWarning for logging.warn(), PR #49

0.4.5

• bugfix: Remove bogus assert False code in recv() that resulted in AssertionError introduced in version 0.4.0 commit-id 9b03fc2, PR #29.

Bugfixes for retry parameter, large file transfers.

• bugfix: Large file transfers in send() were more likely to fail for
  small values of retry: This value should be the maximum failures per
  block transfer as documented, but was improperly implemented as the number
  of failures allowed for the total duration of the transfer, PR #21 <https://github.com/tehmaze/xmodem/pull/21>_.
• bugfix: send(retry=n) and recv(retry=n) would not retry n-1
  times, rather than n times as documented, causing 'retry=1' to never
  retry, for example.