Fix User Guide Search button issue

Signed-off-by: Hashem Qolami <hashem@qolami.com>
Update user_agents.php

Added Win 8.1 user agent to the array
Added post-increment for $count

It has been added the missing post-increment for variable $count.
Merge pull request #2544 from HashemQolami/user-guide-patch

Fix User Guide CSS Issue
[ci skip] Add a missing semicolon in the docs css
[ci skip] Manually apply PR #2746 and remove other -moz-box-shadow and -webkit-box-shadow usage
A tiny improvement in ruri_string()
[ci skip] Remove a few spaces
Make CI_FTP::mkdir()'s first parameter mandatory (optional doesn't make sense)
FTP class improvements

 - Make changedir()'s first parameter mandatory (optional doesn't make sense)
 - Fix a few typos (langfile included)
Make CI_Lang::line()'s first parameter mandatory (optional doesn't make sense)
Merge pull request #2768 from porquero/patch-1

Added post-increment for $count
Merge pull request #2753 from SirDre/patch-1

Update user_agents.php
[ci skip] Some spaces & docblock fixes
Make CI_Unit_test::set_test_items()'s parameter mandatory (optional doesn't make sense)
Make CI_Input::set_cookie() and cookie helpers set_cookie(), get_cookie(), delete_cookie()'s first (name) parameter mandatory
Make CI_Form_validation::error()'s first parameter mandatory and add a typehint for CI_Form_validation::error()
[ci skip] Fix a docblock typo
Make CI_Loader methods library(), driver(), vars() and language()'s first parameters mandatory and fix a docblock
Make CI_Session's set_userdata(), set_flashdata(), set_tempdata(), unset_userdata() and unset_flashdata()'s first parameter mandatory