Log Message:
Update to 1.4.19:

Fixes

    Fix endianness detection during configure.
        Fixes a performance regression with binary protocol (up to 20%)
    Fix rare segfault in incr/decr.
    disable tail_repair_time by default.
        Likely not needed anymore, and can rarely cause bugs.
    use the right hashpower for the item_locks table. Small perf improvement.
    Fix crash for LRU crawler while using lock elision (haswell+ processors)