Make MappedLocal::isLocal() true like for Local

Missed in 788c8540aa6aac50795c37b088eeaa561d44b86c
Check file existance in MappedLocal in hasUpdated()

Only fixed in Local by eeee9eacea333035e22ef3ed938e36f56bc762cd
Check return of disk_free_space before returning it

Local changes copied from ed8359737199a8a6640986e00df80d971aa6e1d7
and 25370fcb8235d2129cab0f8a5843c4784b3673d0
Check whether file exists before trying to touch() it

Local changes from d069ee8a8bce6a08d8b7921ad378c60af2a0439e
and 258ad38fd3c1e3cdc4ec20238b166e78c334b814
Also clearstatcache() in MappedLocal before using the stats

Local change 283c10f010f5da4ca0b6b7658ac1fa730b8858bf
Merge pull request #12469 from owncloud/issue/12460-port-local-changes2mapped

Issue/12460 port local changes2mapped