adding new cli script to rescan files

make log date configurable, default to iso 8601

Port log level filtering from OC_Log_Owncloud to OC_Log_Syslog.

app migrate: Use = instead of LIKE as described in the comment above.

Simplify OC_DB transaction functions

Add ocimage unittest

Make default language configurable via config.php

add OC.Breadcrumb.show(dir, filename, link)

Don't throw a fatal, if is_file() parameter isn't a 'valid path', but only a data/base64-string.

Use !== and === in files_trashbin app

make sure the first breadcrumb item is inserted before any other elements in the topbar

a 'valid path', but only a data/base64-string.

Related to #4283

Use file_get_contents() and base64_encode(file_get_contents()),
to load from data and base64, to cover more cases

data() somehow does not return, what file_get_contents() returns,
so I skipped related tests.

Fix calculating size for empty folders