Install Windows service to run as the current user

[Petr Nejedly]

http://nsis.sourceforge.net/NSIS_Simple_Service_Plugin

http://komma8komma1.googlecode.com/svn-history/r364/trunk/HTInstaller/Installer.nsi

http://komma8komma1.googlecode.com/svn-history/r364/trunk/HTInstaller/MSWAuthenticate.nsh

It should give possibility to enter another username/password as well. It should fix network drive sharing and librtmp FFmpeg problems.

librtmp might be failing as it cannot write the .swfinfo file for the current user (http://forum.serviio.org/viewtopic.php?f=8&t=3039&start=20#p20220)