severity_to_s is called with every captured log statement.   Used a hash to boost the performance a little bit -- http://stackoverflow.com/questions/4178240/which-is-faster-in-ruby-a-hash-lookup-or-a-function-with-a-case-statement
path_to_s is called with every captured log statement.   Memoizing the delimiter (rather than having to fetch it via method call from the Manager every time) should boost the performance a little bit.
Latest ruby profiler information reflecting performance improvements
Bump the version to 0.11.0