Runtime fixes for C# Snippet.

Changes to make the c# snippet more accessible to a wider variety of skill level and resolve certain runtime issues. 

Added Content-Type to header loop to prevent improper attempt to add to Header Collection. 
Fixes attempt to write the content length to the request during the write process. 
Fixes issue where the bytes may not be written to underlying stream. 
Adds the common SSL certificate hook that can be uncommented by developer.