Fix authentication for bulk tracking

refs #4135
Merge branch 'master' of https://github.com/piwik/piwik
Fix syntax error. VisitExcluded is not an Exception, nor is it ever thrown
Fix a few typos
Change description of ip_address_mask_length setting in global.ini.php

After enabling AnonymizeIP to mask IPv6 addresses the notion of this setting had to be changed to represent a masking level rather than a mask length.
Merge branch 'master' of https://github.com/piwik/piwik