Set CLIENT_VERSION_IS_RELEASE, bump build to 0.8.2.1
translations update 2013-05-19 (for 0.8.2 release)

- integrates current translations from Transifex
- new translation: af_ZA
CreateNewBlock performance improvements
Merge pull request #2677 from sipa/fastcreate

CreateNewBlock performance improvements
More bestblock records in wallets

Write bestblock records in wallets:
* Every 20160 blocks synced, no matter what (before: none during IBD)
* Every 144 blocks after IBD (before: for every block, slow)
* When creating a new wallet
* At shutdown

This should result in far fewer spurious rescans.
Merge pull request #2649 from Diapolo/translations

translations update 2013-05-19 (for 0.8.2 release)
Merge pull request #2652 from gavinandresen/version_0.8.2_final

Set CLIENT_VERSION_IS_RELEASE, bump build to 0.8.2.1
Merge pull request #2682 from sipa/morewalletbb

More bestblock records in wallets
doc/README was replaced by README.md