DB schema update after renaming the tasks to activities.
DB schema update after renaming the tasks to activities.

wtag/bookyt,silvermind/bookyt,gaapt/bookyt,gaapt/bookyt,xuewenfei/bookyt,xuewenfei/bookyt,wtag/bookyt,hauledev/bookyt,hauledev/bookyt,silvermind/bookyt,silvermind/bookyt,huerlisi/bookyt,gaapt/bookyt,huerlisi/bookyt,huerlisi/bookyt,hauledev/bookyt,silvermind/bookyt,wtag/bookyt,hauledev/bookyt,gaapt/bookyt,xuewenfei/bookyt