Make a file that includes Hatohol's constants for python sources.
[hatohol-actor-mail] Check the passed event type passed.
[hatohol-actor-mail] Clean up.
[hatohol-actor-mail] Check the passed trigger status.
[hatohol-actor-mail] Check the passed trigger severity.
[hatohol-actor-mail] Show severity as a string if possible.
[hatohol-actor-mail] Implement code to generate mail body.
Define PREFIX and LIBEXECDIR.
Include config.h if it exists.
Add ConfigManager::getActionCommandDirectory() and ConfigManager::setActionCommandDirectory().
Add a test file I forgot to add in the previous commit.
Add ConfigManager::getResidentYardDirectory() and ConfigManager::setResidentYardDirectory().
Restrict a directory of actions.
Add missing include statements.
Add a missing license header.
Restrict a path of resident type action.
Remove the asynchronus signal handler to detect the child exit.

The connection with MySQL server sometimes disconnects in a test
on TravisCI. I guess this is due to the interruption of the asynchronus
signal handler for SIGCHLD, from the following two reasons.
(1) Error message contains "system error: 4"
    (4 may mean EINTR)
(2) The frequency of the error has increased after tests that use
    many child processes and kill them, was added.

This patch prevents the interput by the asynchronus signal handler
and collects children by the dedicated thread and .
Remove the temporary block of SIGCHILD, because the signal handler was removed in the previos commit.
Parse the siginfo on the ActorCollector thread.

Previously we use the asynchronus signal handler. So information about
the child is parsed on the GLIB's event handler where any function
can be called. Now we have the dedicated thread for waiting the child.
This patch makes the thread parse them to improve the performance by
removing communication between threads.
Check the result of the DB update.