ALLJOYN-2215 Prevent compiler warning from Visual C++

In our build system we are choosing to ignore the C4800 compiler warning people
using AllJoyn may not want to ignore that warning.  This change will prevent the
C4800 warning from occurring when the Message.h header file is include in a
project.

Change-Id: Iaf40711df5d9131072d49c281d83b3cd586a7190
ALLJOYN-577: Updated comment and test to use correct values

The test should have said the AllJoyn array size limit was 2^17
the test should also use the same size limit.

Change-Id: I52b0a0780a61015b902ba467084e988c3c831127