Fix opendap.test.TestMisc - underlying data changed
check if directory exists
NCDC file scan problem;
DiskCache2 not checking is dir already exists;
Grib1 Time Partition bugs;
GribCollection.getIndexFile() not checking for cache
Merge remote-tracking branch 'origin/target-4.3.15' into target-4.3.15
Merge branch 'target-4.3.15' into target-4.3.16

Conflicts:
	opendap/src/test/data/baselinemisc/dods.cdl
Merge remote-tracking branch 'origin/target-4.3.16' into target-4.3.16
merge conflicts
one more grib1 imePartition bug