Add ASSERTs, improve documentation and the variety of tests for AlignRpcPtr/UndoAlignRpcPtr.
Based on comments by Serge Gautherie.
svn path=/trunk/; revision=74323
Implement the undocumented AlignRpcPtr and UndoAlignRpcPtr functions used by many Rpc* functions in spoolsv according to traced callchains.
I could reverse engineer them entirely using rohitab.com's API Monitor and black-box testing.
I also add documented tests covering all cases I found out. We now pass 17/17 tests on Windows Server 2003 and ReactOS.
Also const-ify a parameter in PackStrings.
svn path=/trunk/; revision=74297