The network strikes back (1.4.9)

Geth 1.4.9 is a reversal release to undo the code changes that went into the 1.4.8 "DAO Wars" soft-fork release, as the soft-fork was deemed too vulnerable to DOS attacks, opening up the entire Ethereum network to resource abuse by malicious users.

Most importantly, this release reverts a data race introduced by the rushed soft-fork that can lead to miners crashing if they are running transactions simultaneously with importing blocks from the network. Thank you @9600- for finding this!

Additionally, the previously release's soft-fork code required a non-insignificant performance impact even when the soft-fork is not enacted, making this current release at the same time a minor performance boost compared to 1.4.8.