Move solution directly to /src dir.
Update TLSchema, compiler template.

Huge refactoring of TLSchema compiler. Added support for several
built-in types.

TLSchemaCompiler completely removed and all functional now in the
TLSchema class.
Add 'MethodsInterfaceName' arg to the compiler.
Compiler template: type interfaces now 'partial's.
Fix: compiler must not add System.Object type.
Add TLObjectWithCustomSerializerAttribute.
Add TLSerializersBucketFacts.
Update TLRig serializers preparation from assembly.

Now TLRig.PrepareSerializersForAllTLObjectsInAssembly() method will
prepare serializers for types attributted with TLObjectAttribute and
TLObjectWithCustomSerializerAttribute.
Update version to 0.8.
Merge branch 'develop'