ALLJOYN-2210 Clean up warnings reported by the windows compiler

Prevent warning from compiler when casting from double to integer. In JavaScript
all numbers are stored as 64-bit doubles and must be converted to a native type.
The conversion will result in conversion warnings from the compiler unless we
explicitly cast the double to the desired data type.

Change-Id: I3f5e2638255685415681a3f60c95db0518082dc6