Bring SWMR-related tools changes from revise_chunks to develop.

hl/tools/testfiles/w-ext-cmpd-ff3.ddl

@@ -0,0 +1,10 @@
+Opened "TEST.h5" with sec2 driver.
+Monitoring dataset /DSET_CMPD...
+dimension 0: 10->13 (increases)
+    Data:
+        (10) {{{2}}, {2}}, {{{3}}, {3}}, {{{4}}, {4}}
+dimension 0: 13->12 (decreases)
+dimension 0: 12->1 (decreases)
+dimension 0: 1->3 (increases)
+    Data:
+        (1) {{{2}}, {2}}, {{{3}}, {3}}