edify extensions for OTA package installation, part 1

Adds the following edify functions:

  mount unmount format show_progress delete delete_recursive
  package_extract symlink set_perm set_perm_recursive

This set is enough to extract and install the system part of a (full)
OTA package.

Adds the updater binary that extracts an edify script from the OTA
package and then executes it.  Minor changes to the edify core (adds a
sleep() builtin for debugging, adds "." to the set of characters that
can appear in an unquoted string).
diff --git a/Android.mk b/Android.mk
index 8c1de73..bfb1bed 100644
--- a/Android.mk
+++ b/Android.mk
@@ -44,4 +44,6 @@
 include $(commands_recovery_local_path)/minzip/Android.mk
 include $(commands_recovery_local_path)/mtdutils/Android.mk
 include $(commands_recovery_local_path)/tools/Android.mk
+include $(commands_recovery_local_path)/edify/Android.mk
+include $(commands_recovery_local_path)/updater/Android.mk
 commands_recovery_local_path :=