Fix for lost items on save/load

[1942rob]

Issue #2356

[Zireael07]

I luff you. Putting back playing until this is merged in.

[CataJenkins]

Build successful!
Refer to this link for build results: http://ci.narc.ro/job/Cataclysm-PullRequests/245/

[ianestrachan]

I don't believe this is correct, see #2358.

This change moves the call to u.inv.load_invlet_cache() to after the code that loads the inventory. That code doesn't have a catch-all else, so it just completely ignores all of the invlet cache lines (which start with 'P'). Then the call to load_invlet_cache occurs, but the ifstream is at the end of the file, so it immediately ends with an empty invlet cache.

Please correct me if you think I'm wrong, but I believe that this PR will break the invlet cache feature.

[1942rob]

Ahh yes, I screwed up there.