Update to Configuration Storage

[Zi-SH]

This is a direct modification to the changes by pull #908 , and as discussed in issue #918 .

• Introduce ConfigStorage, which brings defines configuration storage in line with the Roaming/XIVQuickLauncher folder on windows.
• Modification to the default FFXIV config folder location, with logic to attempt detection and usage of old configs to make moving less painful.
• Modification to the default dalamud.ini location

This pull is in response to my discussions with @rekyuu