doc: eliminate sphinx warnings

This patch eliminates the following sphinx warnings.

> ryu/doc/source/parameters.rst:47: ERROR: Unexpected indentation.
> ryu/doc/source/step_by_step.rst:1: WARNING: malformed hyperlink target.
> ryu/doc/source/step_by_step.rst:164: ERROR: Inconsistent literal block quoting.
> ryu/doc/source/step_by_step.rst:229: WARNING: Bullet list ends without a blank line; unexpected unindent.
> ryu/doc/source/step_by_step.rst:278: WARNING: Bullet list ends without a blank line; unexpected unindent.
> ryu/doc/source/step_by_step.rst:320: WARNING: Bullet list ends without a blank line; unexpected unindent.
> ryu/doc/source/step_by_step.rst:329: WARNING: Bullet list ends without a blank line; unexpected unindent.
> ryu/doc/source/step_by_step.rst:333: WARNING: Bullet list ends without a blank line; unexpected unindent.
> ryu/doc/source/step_by_step.rst:357: WARNING: Bullet list ends without a blank line; unexpected unindent.
> checking consistency... ryudoc/source/parameters.rst:: WARNING: document isn't included in any toctree

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
doc: man pages for ryu-manager and ryu-client

In order to quieten rpmlint
> ryu.noarch: W: no-manual-page-for-binary ryu-manager
> Each executable in standard binary directories should have a man page.
>
> ryu.noarch: W: no-manual-page-for-binary ryu-client
> Each executable in standard binary directories should have a man page.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
tests: make run_tests.py, test_lib.py executable as it includes #!

rpmlint requires it as follows.

> ryu.noarch: E: non-executable-script /usr/lib/python2.7/site-packages/ryu/tests/run_tests.py 0644L /usr/bin/env
> ryu.noarch: E: non-executable-script /usr/lib/python2.7/site-packages/ryu/tests/test_lib.py 0644L /usr/bin/env
> This text file contains a shebang or is located in a path dedicated for
> executables, but lacks the executable bits and cannot thus be executed.  If
> the file is meant to be an executable script, add the executable bits,
> otherwise remove the shebang or move the file elsewhere.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>