fixed xsd:all when used in conjunction with substitution groups adding

* xmlschemas.c: fixed xsd:all when used in conjunction with
  substitution groups
* test/schemas/allsg_* result/schemas/allsg_*: adding specific
  regression tests, strangely missing from NIST/Sun/Microsoft
  testsuites
Daniel
diff --git a/result/schemas/allsg_0_5 b/result/schemas/allsg_0_5
new file mode 100644
index 0000000..2689cf0
--- /dev/null
+++ b/result/schemas/allsg_0_5
@@ -0,0 +1 @@
+./test/schemas/allsg_5.xml fails to validate