Bottle-necks in using Jumanpp

[Kensuke-Mitsuzawa]

1. It tends to cause exception in processing the first request.
2. It tends to cause an exception when we try to process the huge amount of text.

Improvement

1

It's better to put command to process dummy text just after package initializes a jumanpp process.

2

It's better to put an automated-restart procedure in the jumanpp process handler.