Revert "Hotfix: Only orb_copy items in mavlink app if the timestamp changed"

This reverts commit a9653fa10db3884d3d17ee33f80f23aa2e3ef842.
Merge pull request #1076 from PX4/mavlinkrevert

Revert "Hotfix: Only orb_copy items in mavlink app if the timestamp changed"
Merge branch 'master' of git://github.com/PX4/Firmware into flapping
Flapping wing controller work.