XWIKI-9905: Fix the list of members for subwikis

* Add "xwiki:" in front of every member of the list if it's not already there
XWIKI-9905: Fix the foreach loop

* Insert the line of adding member in a map into the foreach loop
Fix typo
Merge pull request #256 from woshilapin/XWIKI-9905

XWIKI-9905: Fix the list of members for subwikis.