using lenght istead of count for php 7.1 compatibility

Merge pull request vimeo#6946 from sebkehr/fix_cannot_extend_constrai…

…ned_with_imported_alias

Merge pull request vimeo#6833 from orklah/psl-ci

add PSL back to CI

Merge pull request vimeo#6738 from orklah/generator_and_iterator

don't use is_a with user classes

Merge pull request vimeo#6726 from orklah/crash_intrange

Don't crash on falsy with int ranges

Add catch-all category

Merge pull request vimeo#6421 from weirdan/ftp-resource-to-objects

Merge pull request vimeo#6304 from vimeo/revert-6210-int-range3

Fix space

Improve internals of TIntRange (vimeo#6208)

* Improve internals of TIntRange

* fix PositiveInt aliasing