This patch changes default permission of the gitlab/log directory to
u+rwX,go-w. This is done to make the directory NOT readable by group and
others and to avoid logrotate complaining about it. chmod 755 is not
used to avoid setting executable bit on file within the log dir.

fix formatting issue with self-signed certificate section

also adds comment about updating nginx files during upgrades

* fix code blocks
* Make capitalization of titles consistent - missed some in
https://github.com/gitlabhq/gitlabhq/pull/7576

* Fix some formatting issues
* Make capitalization of titles consistent
* Update image that shows how to select branch

The following error is encountered during the installation of the rugged gem:

Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

    /usr/bin/ruby2.1 extconf.rb
    checking for cmake... no
    ERROR: CMake is required to build Rugged.
    *** extconf.rb failed ***

Update `curl` commands to follow redirects (see
http://curl.haxx.se/docs/manpage.html#-L). Current `curl` commands will
return unexpected results if the requested content has been moved and is
returning information about where it has been moved to. Including the
`-L` option tells `curl` to follow the redirect so the file can be
correctly acquired.

Further changes

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Just a minor fix ;)

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Ruby version updated so it doesn't have the readline bug https://www.ruby-lang.org/en/news/2014/05/09/ruby-2-0-0-p481-is-released/.