Provide WebAPIResource in reviewboard.webapi.resources again.
Provide WebAPIResource in reviewboard.webapi.resources again.

The recent API codebase restructuring moved WebAPIResource into
reviewboard.webapi.base, but older extensions expected this to be found
in reviewboard.webapi.resources. That's completely valid, so now we
provide it there as well.

Older extensions importing the various resource instances will still
need to be updated, though.

bkochendorfer/reviewboard,davidt/reviewboard,bkochendorfer/reviewboard,chipx86/reviewboard,KnowNo/reviewboard,brennie/reviewboard,1tush/reviewboard,sgallagher/reviewboard,1tush/reviewboard,reviewboard/reviewboard,KnowNo/reviewboard,reviewboard/reviewboard,1tush/reviewboard,beol/reviewboard,custode/reviewboard,davidt/reviewboard,sgallagher/reviewboard,bkochendorfer/reviewboard,davidt/reviewboard,custode/reviewboard,brennie/reviewboard,sgallagher/reviewboard,1tush/reviewboard,beol/reviewboard,davidt/reviewboard,KnowNo/reviewboard,chipx86/reviewboard,1tush/reviewboard,KnowNo/reviewboard,1tush/reviewboard,reviewboard/reviewboard,1tush/reviewboard,brennie/reviewboard,reviewboard/reviewboard,custode/reviewboard,brennie/reviewboard,bkochendorfer/reviewboard,chipx86/reviewboard,1tush/reviewboard,beol/reviewboard,beol/reviewboard,sgallagher/reviewboard,chipx86/reviewboard,1tush/reviewboard,custode/reviewboard