Abandoned user-scope install and started on DLL.

I was dumb and didn't realize non-privileged users couldn't install
services. Make the whole effort of supporting installation to %appdata%
a waste. Abandoned basing dialogs on WixUI_Advanced and basing it
instead on WixUI_Installdir.

Added new dialog where user can enter details/credentials and hooking it
into a DLL. Started moving code from main service to DLL.