BUG FIX: SyncDAO: Turn syncToRemote_/syncFromRemote_ into sync strategies
BUG FIX: SyncDAO: Turn syncToRemote_/syncFromRemote_ into sync strategies

Now use syncToRemote_() as sync_() strategy for push-update SyncDAOs and
pollingSync_() as strategy for polling SyncDAOs. This fixes a bug where
syncToRemote_().then(syncFromRemote_()) would capture minimum version number
after syncing new version numbers from the sync-to push; these numbers may be
greater than versions that should be processed during sync-from (and so some
updates will be skipped). pollingSync_() starts by capturing the minimum
version number for syncing, then pushes updates, then pulls updates.

TanayParikh/foam2,foam-framework/foam2,jacksonic/vjlofvhjfgm,jacksonic/vjlofvhjfgm,TanayParikh/foam2,foam-framework/foam2,TanayParikh/foam2,foam-framework/foam2,foam-framework/foam2,jacksonic/vjlofvhjfgm,TanayParikh/foam2,foam-framework/foam2