Update mcs/class/Commons.Xml.Relaxng/Commons.Xml.Relaxng/RelaxngPattern.cs

- Choice of using the parser for compact syntax or not based on the file extension,
in order to allow mixed grammars (e.g. including RNG from RNC).
- Correction in base URI for compact syntax in order to allow including grammar files located in different directories.
Update mcs/class/System.Core/System/TimeZoneInfo.cs

Implementing missing ConvertTime with DateTimeOffset.
Fix for issue 2907. I took Roman Zavalov's patch at https://bugzilla.xamarin.com/show_bug.cgi?id=2907#c10 and reverted the numerous formatting changes that were obscuring the real changes, hopefully making the diff clearer
Unit test for issue 2907, from Josef Semmler's attachment at https://bugzilla.xamarin.com/show_bug.cgi?id=2907#c2
Merged into single file, added assertions
Fix null sessions in HttpContextWrapper.Session
Merge remote-tracking branch 'upstream/master' into fix-for-issue2907-with-no-formatting-changes
do not check order sequence if option /order was not used
Fix the sizeof IL instruction for reference types. Fixes #8448.
Check for nullref exceptions in ves_icall_System_Buffer_BlockCopyInternal () since it is called directly without going through the managed wrapper. Optimize the MONO_CHECK_ARG() macros a bit.
Increase the number of trampoline entries reserved for trampolines.
Unroll the first loop iteration in OBJ_RUN_LEN_FOREACH_PTR ().
Implement support for imported properties with parameters. Fixes #8398
Fix a warning.
Move an sgen debug message to loglevel 2 from 1.
Sweep the heap block containing the object in free_object ().
Reject overload candidates with not enough default parameters before dependency check. Fixes #8466
Prefer indexer over properties with parameters
Fix XML serialization bug

When reflecting a class which inherits serializable members from a
base class, the members of the base class must be serialized using the
namespace set in the subclass unless a namespace has been explicitly
set in the base class. Before the fix, the members were always
serialized using the namespace of the base class, even when not set
(in which case it was using the default empty namespace).

Fixes bug 8468 - XML serialization problem.
Add tests for bug #8468

Conflicts:

	mcs/class/System.XML/Test/System.Xml.Serialization/DeserializeTests.cs