Move some of the tests from t/ into t/defaults-flat.

This lets us move t/default.do out of the way; it was confusing otherwise.

t/defaults-flat/all.do

@@ -0,0 +1 @@
+redo-ifchange c d

t/defaults-flat/c.c.c.b.b.a

@@ -0,0 +1 @@
+chicken

t/defaults-flat/c.do

@@ -0,0 +1,3 @@
+redo-ifchange $1$2.c
+echo c.do
+cat $1$2.c

t/defaults-flat/clean.do

@@ -0,0 +1,2 @@
+rm -f c c.c c.c.c c.c.c.b c.c.c.b.b d \
+	*~ .*~

t/defaults-flat/default.b.do

@@ -0,0 +1,10 @@
+if [ -e "$1$2.a" -o -e "default$2.a" ]; then
+	redo-ifchange "$1$2.a"
+	echo a-to-b
+	cat "$1$2.a"
+else
+	redo-ifchange "$1$2.b"
+	echo b-to-b
+	cat "$1$2.b"
+fi
+../sleep 1.1

t/defaults-flat/default.c.c.do

@@ -0,0 +1,4 @@
+redo-ifchange $1$2.b
+echo b-to-cc
+cat $1$2.b
+../sleep 1.2

t/defaults-flat/default.c.do

@@ -0,0 +1,4 @@
+redo-ifchange $1$2.c
+echo c-to-c
+cat $1$2.c
+../sleep 1.3

t/defaults-flat/default.do

@@ -0,0 +1,4 @@
+redo-ifchange c
+echo default-rule
+cat c
+../sleep 1.4