fix utf8 filenames in ie download response header according to rfc5987, see http://stackoverflow.com/questions/93551/how-to-encode-the-filename-parameter-of-content-disposition-header-in-http

Fall back to default log file if logfile config file not found, suppress writing errors, fixes issue #826

Conflicts:
	lib/base.php

[contacts_api] IAddressBook moved to OCP as it's used by apps to provide access to their contact data

Fixes #730.

to the userExists method both in OCP\User and in OC_User.

give the caller the option to handle the exception

Corrected simple typo

We can't do the loading before matching the route, because some routes
need to do the loading after matching of the route. For example the
navigation detection of the app settings page.