Get generic system test to pass

[jeffkaufman]

We can now run the generic pagespeed system test, but it fails partway through.

This is a tracking bug: if you're working on fixing a bug that it turns up please create new issue for it and link it from here.

Current: TEST: regression test with same filtered input twice in combination

Then: convert meta tags

Then: ModPagespeed=noscript inserts canonical href link

Then: etag not set on gzip-encoded resources in 1.3.6

Then local_storage_cache,inline_css,inline_images,debug debug mode

[jeffkaufman]

None of these issues are showstoppers; recategorizing as lower priority.

[jeffkaufman]

With 14c7fb1 the system test now passes except for three known issues that are already elsewhere in our issue tracker.