Merge pull request #8 from yanak/fix/chatwork

revise chatwork
Merge remote-tracking branch 'origin/fix/chatwork'
revise retrieve db object
revise cache cookie and sending message method
rename a file
create a event notifier class
revise accessor
revise the db path adn create a find method
create a setting tasks method
remove a debug line
uncomment a db updating method
revise db update and create a updating master method
revise message retrieving time
revise retrieving message and rename a method
revise sql and time
revise variable name
update commander