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_3.err b/result/schemas/allsg_0_3.err
new file mode 100644
index 0000000..756473b
--- /dev/null
+++ b/result/schemas/allsg_0_3.err
@@ -0,0 +1 @@
+./test/schemas/allsg_3.xml:6: element gm-B-1: Schemas validity error : Element '{urn:test:foo}gm-B-1': This element is not expected. Expected is one of ( {urn:test:foo}gh-A, {urn:test:foo}gm-A-2, {urn:test:foo}gm-A-1 ).