pkg/webserver: use a custom logger, if provided

http://camlistore.org/issue/479

Change-Id: I41bd0a02d40e9ad94f655b5c1abdfa5db76c7019
Merge "pkg/webserver: use a custom logger, if provided"
importer: add ChildPathObjectOrFunc to let importers find a fitting permanode on miss

Change-Id: I016f30aa9e05a1024c2cdb7b1e8be0a675f73719
picasa: give a title to importer root permanode

Change-Id: I0e259db52060518dfe33f31f0222b169a8c9e0ef
Merge branch 'master' of https://camlistore.googlesource.com/camlistore