Modify testing to only record validation pass/fail

* Changed unit tests to only record known the validation pass/fail
status
 * errors are output as part of the failure message if the result is
 unexpected
 * can turn off validation for each test individually
* Moved some SPV_KHR_vulkan_memory_model tests to be compiled for Vulkan
1.1
diff --git a/Test/baseResults/spv.image.frag.out b/Test/baseResults/spv.image.frag.out
index a544180..0fefd01 100644
--- a/Test/baseResults/spv.image.frag.out
+++ b/Test/baseResults/spv.image.frag.out
@@ -1,8 +1,5 @@
 spv.image.frag
-error: SPIRV-Tools Validation Errors
-error: Capability ImageRect is not allowed by Vulkan 1.0 specification (or requires extension)
-  OpCapability ImageRect
-
+Validation failed
 // Module Version 10000
 // Generated by (magic number): 80007
 // Id's are bound by 395