[ticket/12560] Add methods to set upload and temp paths in plupload

The paths will be reset to the default paths after an upload is complete.

PHPBB3-12560
[ticket/12851] Fix the Font colour button title

PHPBB3-12851
Merge pull request #2766 from marc1706/ticket/12560

[ticket/12560] Add methods to set upload and temp paths in plupload
Merge pull request #2733 from n-aleha/ticket/12851

[ticket/12851] Fix the Font colour button title

* n-aleha/ticket/12851:
  [ticket/12851] Fix the Font colour button title
[ticket/12887] Fix Typo: offest -> offset

PHPBB3-12887
Merge pull request #2773 from bantu/ticket/12887

[ticket/12887] Fix Typo: offest -> offset

* bantu/ticket/12887:
  [ticket/12887] Fix Typo: offest -> offset