Merge pull request #1 from comfortablejohn/master

Merge pull request #1 from txlife/master
change to header and file transfer(unsuccessful)

i tried to implement header function, but don’t know how to do it with
trustcloud.c  I did change codes for client and server. The file
transfer part did not get changed since I failed to get it work.
Merge pull request #2 from txlife/master

changes to header function (only client and server codes got changed)