This commit consists of patches automatically generated for this project on https://scrutinizer-ci.com

In an older version of PHP a file_exists() call would issue a warning
when the file did not exist. This was fixed in later PHP releases. Since
we require PHP 5.3 now, there's no need to supress any error here
anymore. This might even give a minor performance boost.

':' is the field delimiter in the authplain flat text
conf/users.auth.php file, but it's also used as an internal delimiter
for the 'mediawiki' password hash format. Currently using this hash
format corrupts the file

This change escapes ':' as '\:' in any field in the users.auth.php
file, and any '\' as '\\'.

Also adds test cases for escaping modes.

Some parts of dokuwiki (e.g. recent changes, old revisions) can
requests lots of user info (to provide editor names) without
requiring any group information.

This change also implements caching of user info by authmysql &
authpgsql plugins to avoid repeated querying of the DB to retrieve
the same user information.

reloading the user list after the delete action will make sure the count
is always correct.

* code/PHP5 cleanup

This does nothing currently but allows us adding certain things
to the base class later.