Setting up for wiping out all alerts.
Dismiss all posts tools.
AJAX functions for dismissing alerts
Dismiss functionality and AJAX rounded out
Missing parenthesis
Reposition and darken dismiss text.
Preparing labels for future use
Handler to deal with soon to be depreciated

label filters
Apply the delete all filter in the depreciation
Missing parenthesis
Change Previously to Previous

Resolves #440
Makes alerts dismissible.
Merge pull request #450 from PressForward/3.4.x-new-alert-functionality

3.4.x new alert functionality - now dismissible