Log Message:
Update to 0.60.6.1:
    Update to Automake 1.10.3
    Fix a bug which caused a race condition (leading to a likely
    crash) when two threads try to update the dictionary cache at
    the same time.
    Make it very clear that compiling Aspell with NDEBUG is a bad
    idea (see http://aspell.net/ndebug.html) by outputting a warning
    when building with NDEBUG defined.
    Numerous other minor updates and bug fixes.