Possibility to collapsed threads with persistance
applied comments and fix bug where the folded threads were saved only after refreshing the entire page
Manage the collapse UIDs save in the user settings
Applied comments
bugfix where an exception was raised if threadsCollapsed is undefined
applied comments
Update NEWS file
applied comments
bugfix for new user without userSettings.mail
Merge pull request #54 from alexcloutier/feature/FoldingThreads

Feature/folding threads