Limit Glide cache to 200 MB

[msfjarvis]

Gonna take a while to see if it truly works so letting this be a draft for now

[AbsurdlySuspicious]

root@localhost /d/d/m/cache# du -hd 1 | sort -h
212K    ./disk_lru_cache
22M     ./WebView
202M    ./image_manager_disk_cache
224M    .
root@localhost /d/d/m/cache# du -hd 1 | sort -h
212K    ./disk_lru_cache
22M     ./WebView
201M    ./image_manager_disk_cache
223M    .

I scrolled the feed and downloaded some pretty large images between these two du invocations so this works good

[AbsurdlySuspicious]

Maybe there's also some sense in making this limit configurable. This is surely matter of another PR though