execute moment time to handler block.

- if you want to process in the block with respect to use time.
add README to block in time
rollback log format

- this reason is please show this url.
  https://github.com/tomykaira/clockwork/pull/61
log include time check testcase removed.
Fix description in README
Move the new handler argument test to ManagerTest
Merge branch 'when_job_run_time_fix'
Version 0.7.0

Changes:

    Change the structure of Clockwork module (by @TakatoshiMaeda)

    `include Clockwork` style is no longer recommended.
    Use `module Clockwork; ... ; end` instead.

    Pass the time when a job is prepared to the handler (by @TakatoshiMaeda)

    clockworkd supports `--dir` argument to set the current working directory of daemon (by @ajsharp)