Fix issue with parse_ini_file which strip out \\ into \ in the cache .ini files

There is an issue with parse_ini_file which for some reason change the \\ into \ in the cache ini file when Garden is running from a network share.

For example:
gdn = "\\networkshare\folder\Garden/library/core/class.gdn.php"

Will become:
gdn = "\networkshare\folder\Garden/library/core/class.gdn.php"

This fix will produce 
gdn = "//networkshare/folder/Garden/library/core/class.gdn.php"

This fix will enable Garden to run on a network share where without it, Garden will hit a "bonk" screen.