fix the MSI installer so it can set LOCAL_CONFIG_FILE and fix bugs in config_fetch #4092
the installer now recognises LOCALCONFIG=<file> passed to the installer, and if
<file> begins with http, it will put that into LOCAL_CONFIG_FILE using pipe config and
the config_fetch tool.  Fixed bugs in the config_fetch tool so that it no longer changes
the file it gets back from the url.
===VersionHistory:Pending===