Reduce the memory usage of the operator list.
Fixes glyphs with invalid flags
Merge pull request #3913 from brendandahl/int-ops

Reduce the memory usage of the operator list.
Merge pull request #3887 from yurydelendik/bug903856

Fixing glyphs with invalid flags
Don't traverse all pages to get a single page.
Merge pull request #3848 from brendandahl/page-refs

Don't traverse all pages to get a single page.