hush: support $_NUMBERS variable names

diff --git a/shell/hush_test/hush-vars/var.right b/shell/hush_test/hush-vars/var1.right
similarity index 100%
rename from shell/hush_test/hush-vars/var.right
rename to shell/hush_test/hush-vars/var1.right
diff --git a/shell/hush_test/hush-vars/var.tests b/shell/hush_test/hush-vars/var1.tests
similarity index 100%
rename from shell/hush_test/hush-vars/var.tests
rename to shell/hush_test/hush-vars/var1.tests
diff --git a/shell/hush_test/hush-vars/var2.right b/shell/hush_test/hush-vars/var2.right
new file mode 100644
index 0000000..40bf4bf
--- /dev/null
+++ b/shell/hush_test/hush-vars/var2.right
@@ -0,0 +1,2 @@
+http://busybox.net
+http://busybox.net_abc
diff --git a/shell/hush_test/hush-vars/var2.tests b/shell/hush_test/hush-vars/var2.tests
new file mode 100755
index 0000000..1292410
--- /dev/null
+++ b/shell/hush_test/hush-vars/var2.tests
@@ -0,0 +1,4 @@
+_1=http://busybox.net
+
+echo $_1
+echo ${_1}_abc