Fix the help text process and the generated wrong help

The wrong help text of bash-completion is generated by the process of
choosing first line from the source code comment. We should get the all
help text from the source code comment, and use it.

So this commit removes this unnecessary process, and also fix the
README.rst for proper help text.

Fixes bug 1206005

Change-Id: Id4f5b6a7722197f09eb366ba8f3e643e1af91805
Merge "Fix the help text process and the generated wrong help"