[BUGFIX] Respect loadFancybox setting

The fancybox library will be loaded when the loadFancybox setting is
TRUE. Before it was checked if loadjqueryForm is TRUE which does not
make sense.
[BUGFIX] Remove duplicate userGroupAllowEditFiles constant

The constant is now defined only once.
[BUGFIX] Provide userGroupAdmin admin setting

The constant userGroupAdmin is now loaded in the userGroupAdmin
persistence setting so that it is available in the code.
[BUGFIX] Fix close button for delete dialog

Since jQuery is running in noConflict mode jQuery must be used as
variable instead of $. The variable name is replaced in the list
template.