[XenConcept] Prefix listing 2.1.0

Rename to Prefix listing
Update for XF 2.3

Add :

• Add support for XenForo Resource Manager
• Add support for XenConcept Project Manager

Note : This version require XF 2.3

• Fixed a bug with option Number of prefixes to display

• Fixed a bug with option Do not show prefixes with less then X threads

• The add-on is now compatible with the [Xon] Multi Prefix add-on.

New feature:

• We have improved the performance of the function that counts the number of threads per prefix.
• Added permission to view the block

• Fix a bug with the display order

• Fix a disgn

• Fix responsive disgn
• Code improvement

• Fixed a bug when counting threads

• [Bug Fix] The add-on does not count the sticky threads
• Code improvement