If an authentication plugin thinks that a user should be able to log in, and furthermore thinks that it is able/allowed to automatically create user accounts, then it is now able to do just that. The authentication API now has a new method - can_auto_create_users() - to define whether each authentication instance feels it can/should be able to do this.

If the instance thinks it can, it needs to export some information through the get_user_info method in order to populate the user account. Although this may change shortly to be optional, with the users instead being forced to enter any information that is required that they haven't otherwise filled out.

Ensure that we retrieve timestamps from the database in the correct form when trying to log in a user, otherwise they get stored in the object in the wrong form, leading to pain later.

Use the new 'isFull' method of the institution class instead of manually working out if an institution is full.

Such a test is done in several places in the codebase, sometimes incorrectly. Makes sense to centralise it.

Conflicts:

	htdocs/lib/db/upgrade.php

Correct the path to the view layout preview thumbnails, so it works when Mahara is installed in a subdirectory.

Conflicts:

	htdocs/lib/form/elements/userlist.php

Firstly, an over-enthusiastic optimisation I was responsible for broke the replacement of downloadtemp images, especially on sites which are not installed at the root of a domain. Then, some greedy regexes meant that if there was more than one image in the post, only one of them would have the URL fixed properly. The same bug was happening again when posts were being displayed in views.

This patch fixes these problems, and contains a blog database upgrade to fix existing broken paths.

for register, login, forgotten password, contact

Respect the system include path. This allows system versions of libraries to be used if Mahara doesn't include them - e.g. when being debian packaged.