change warning level for "Trying to synchronize variable '%s' with no storage" to 4 from 2

Carpet does this since Dec 22 20:37:26 2010 to avoid many many warnings when using GRHydro. GRHydro contains SYNC statements in schedule.ccl since it is impossible to tie a SYNC statement to an if statement, one has to spell out every single SCHEDULE statement for all combinations of grid functions that might have storage.

Keyword: PUGH