[jsk_robot_startup/smach_to_mail] Set sender address and receiver address from rosparam

[tkmtnt7000]

This PR enables to set mail address from rosparam.
Related to jsk-ros-pkg#1558

[k-okada]

@tkmtnt7000 thank you, please add error checking code, when no param is set, use default value or raise errors

[tkmtnt7000]

Sorry for late.
I add error checking code(354bd5a)

[tkmtnt7000]

I think there might be some demand that we don't want to write their email address (robot or personal one) on github, so I make it possible to set the email address from the yaml file as well. The implementation is based on email_topic.py.

[k-okada]

@tkmtnt7000 pleaes update documents,
https://github.com/jsk-ros-pkg/jsk_robot/tree/master/doc/jsk_robot_common/jsk_robot_startup

I think there might be some demand that we don't want to write their email address (robot or personal one) on github, so I make it possible to set the email address from the yaml file as well. The implementation is based on email_topic.py.

In my opinion, we need to be very careful on using /var/lib,

1. we put information on '/var/lib/robot' because we do not want to share these inforamtion on CVS
2. Most of email address is already listed on package.xml.
3. The more information we put in '/var/lib/robot', the more we want to put these information on CVS

T:今後この辺りもバージョン管理できたら履歴が残っていいかも、と思いました
Y:/var/lib以下ってこと？この辺りというのは
T:あ、そうです

4. may be I sould not allow to use yaml file in Add ros node to send email based on received ros topic jsk-ros-pkg/jsk_robot#1388 ...
5. If we want to use system-wide information, we should use rosparam, so that you can access from different machine.

--> Please discuss with @708yamaguchi and others, if we can remove /var/lib/robot/email_topic.yaml, please remove e58ac07, if that features is useful or already widely used, please simply update the document.

[tkmtnt7000]

@tkmtnt7000 pleaes update documents,
https://github.com/jsk-ros-pkg/jsk_robot/tree/master/doc/jsk_robot_common/jsk_robot_startup

OK. I'll write document about smach_to_mail.py overview first.

In my opinion, we need to be very careful on using /var/lib,

we put information on '/var/lib/robot' because we do not want to share these inforamtion on CVS
Most of email address is already listed on package.xml.
The more information we put in '/var/lib/robot', the more we want to put these information on CVS
T:今後この辺りもバージョン管理できたら履歴が残っていいかも、と思いました
Y:/var/lib以下ってこと？この辺りというのは
T:あ、そうです
may be I sould not allow to use yaml file in jsk-ros-pkg#1388 ...
If we want to use system-wide information, we should use rosparam, so that you can access from different machine.
--> Please discuss with @708yamaguchi and others, if we can remove /var/lib/robot/email_topic.yaml, please remove e58ac07, if that features is useful or already widely used, please simply update the document.

I understand. I will discuss with @708yamaguchi and other members whether to use /var/lib or not.
Surely, I also think that the more parts of the system that are not shared on CVS, the harder it is to find problems when they occur....