t/*: rearrange tests into numbered directories.

It was getting way too ad-hoc in there.  Let's reorganize the tests so that
there's a good, obvious, suggested sequence to run them in.

t/all.do

@@ -1,2 +1,10 @@
-redo-ifchange hello yellow bellow defaults-flat/all defaults-nested/all \
-	example/all
+# builds 1xx*/all
+/bin/ls 1[0-9][0-9]*/all.do |
+sed 's/\.do$//' |
+xargs redo
+110-compile/hello >&2
+
+# builds the rest
+/bin/ls [2-9][0-9][0-9]*/all.do |
+sed 's/\.do$//' |
+xargs redo-ifchange