ip2country 7.x-1.4

Some new features accompanied by a host of minor bug fixes as well as code and testing improvements.

The most significant change was from issue #1592278: Implement a scheme for updating the data safely, without first deleting the existing data. Also implemented are data integrity checks using the MD5 checksum and database summary information downloaded from the RIR server. The end result is that database updates happen completely and without error, or they don't happen at all, and the module continues to operate with a full data base while the update is happening. Error reporting has been improved so that the watchdog will report update failures and their cause.