Use user icon instead of contact

Signed-off-by: Jonathan Swaelens <jonathan.swaelens@fusiondirectory.org>

Resolves issue when applying and creating from template.

Automatic snapshots are well taken before modifications and take all user info.

Automatic removal of snapshots for users is now operational.

Fixes a typo in the object call SnapshotHandler.

Automatic snapshot operational. Upon user modification,
object snapshotHander is instantiated and call  createSnapshot.

first concept of automatism within class user for snapshot.

("in LDAP", or "in the LDAP directory", but not "in the LDAP")

Full code style as been reworked to match 1.4

Code style continue

Continuity of code style fixing

Space parenthesis after fnc name fixed
On function creation

Fixing codestyle

This reverts commit 46b03343.

Fixing codestyle

Reading of old format when modifiers where in use was broken.

issue #6163

issue #6181

In some cases they end up shown to the user and should be
 understandable.

issue #6170

The new format is method|locked|password, which makes a lot more sense
 than storing a bogus hash for templates, and fixes problems with clear
 method.

The code can still read the old format so transition should be fine.

issue #6163

This will improve webservice error context.

issue #6071

issue #6072

This replaces save_object and execute methods by 3 methods:
readPost - Reads POST data
update - Update object state
render - Render HTML UI

The point is to avoid reading POST and rendering HTML when this is not
 needed (when doing stuff through the webservice for instance).

It’s also more consisent across FD with all classes handling some kind
 of dialog implementing the new interface FusionDirectoryDialog which
 makes sure these 3 methods are implemented.

issue #6072

PHP<7.2 do not like changing typing of the attribute in inheriting
 classes, even if it’s to a larger constraint.

issue #6106

issue #6071

issue #6071

Also improve error messages

issue #6100

Ppolicy plugin now stores the full dn of the default ppolicy instead of
 only the cn.

issue #6093

This avoids problems with templates not behaving like LDAP data.
I tried to use the option in all cases where the array is stored for
 futur use, and of course especially for simplePlugin.

issue #6080

issue #6054

issue #6053

Now array values are checked to have correct format, and string values
 are used as the new password using default password method.

issue #6052

Avoid hard-coded limits and instead have a configuration option to set
 maximum size for user avatars

issue #6049

This makes more sense since it means asking for password at creation,
 and not changing password when applying.

issue #6035

When hash is set but not the password value (which is the default if you
 leave the template fields empty), applying the template to a user would
 result in changing its password, even if he already uses the same hash
 method.
With this change it will leave its password alone if it already uses the
 method, and if the method changed it should complain and ask for a new
 password.
This should avoid users erasing passwords by mistake.

issue #6035

issue #6034

issue #5785

Hide nonreadable fields
Hide nonreadable sections
Color nonwritable fields text
Hide nonwritable subattributes
Use CSS for must red star

issue #5858

issue #6001

Moved userinfo related functions as methods in userinfo
Moved ppolicy account expiration check to expired_status method
Split ppolicy fetch in a method so that it can be used by expiration
 warning detection later.

issue #6001