Make lightbox canvas feature cross-browser compatible.
Make lightbox canvas feature cross-browser compatible.

This makes the canvas zoom and pan feature cross-browser compatible in
a few ways:

1. Replace deprecated `mousewheel` event in favor of the similar and
cross-browser event `wheel`.

2. Create approximate substitute for `e.movementX` and `e.movementY`
values that are missing in Safari.

brainwane/zulip,kou/zulip,timabbott/zulip,showell/zulip,shubhamdhama/zulip,verma-varsha/zulip,showell/zulip,synicalsyntax/zulip,zulip/zulip,rishig/zulip,andersk/zulip,Galexrt/zulip,brainwane/zulip,brockwhittaker/zulip,vaidap/zulip,timabbott/zulip,dhcrzf/zulip,synicalsyntax/zulip,mahim97/zulip,dhcrzf/zulip,amanharitsh123/zulip,shubhamdhama/zulip,vaidap/zulip,hackerkid/zulip,punchagan/zulip,eeshangarg/zulip,hackerkid/zulip,dhcrzf/zulip,eeshangarg/zulip,kou/zulip,shubhamdhama/zulip,tommyip/zulip,jackrzhang/zulip,showell/zulip,tommyip/zulip,Galexrt/zulip,synicalsyntax/zulip,rishig/zulip,Galexrt/zulip,rht/zulip,Galexrt/zulip,shubhamdhama/zulip,rishig/zulip,Galexrt/zulip,vaidap/zulip,showell/zulip,Galexrt/zulip,andersk/zulip,vaidap/zulip,tommyip/zulip,shubhamdhama/zulip,brainwane/zulip,zulip/zulip,hackerkid/zulip,shubhamdhama/zulip,showell/zulip,eeshangarg/zulip,timabbott/zulip,brockwhittaker/zulip,amanharitsh123/zulip,kou/zulip,mahim97/zulip,jackrzhang/zulip,punchagan/zulip,dhcrzf/zulip,dhcrzf/zulip,vaidap/zulip,showell/zulip,dhcrzf/zulip,rht/zulip,brockwhittaker/zulip,kou/zulip,brainwane/zulip,tommyip/zulip,rht/zulip,zulip/zulip,brainwane/zulip,amanharitsh123/zulip,amanharitsh123/zulip,synicalsyntax/zulip,shubhamdhama/zulip,Galexrt/zulip,eeshangarg/zulip,mahim97/zulip,zulip/zulip,rishig/zulip,tommyip/zulip,andersk/zulip,punchagan/zulip,brainwane/zulip,hackerkid/zulip,verma-varsha/zulip,rishig/zulip,eeshangarg/zulip,punchagan/zulip,synicalsyntax/zulip,verma-varsha/zulip,andersk/zulip,tommyip/zulip,brockwhittaker/zulip,rht/zulip,kou/zulip,jackrzhang/zulip,timabbott/zulip,punchagan/zulip,eeshangarg/zulip,timabbott/zulip,timabbott/zulip,rht/zulip,mahim97/zulip,brockwhittaker/zulip,jackrzhang/zulip,hackerkid/zulip,verma-varsha/zulip,brockwhittaker/zulip,kou/zulip,rht/zulip,andersk/zulip,andersk/zulip,hackerkid/zulip,rht/zulip,amanharitsh123/zulip,dhcrzf/zulip,jackrzhang/zulip,verma-varsha/zulip,zulip/zulip,mahim97/zulip,punchagan/zulip,rishig/zulip,hackerkid/zulip,synicalsyntax/zulip,showell/zulip,tommyip/zulip,verma-varsha/zulip,andersk/zulip,jackrzhang/zulip,zulip/zulip,rishig/zulip,zulip/zulip,vaidap/zulip,jackrzhang/zulip,brainwane/zulip,mahim97/zulip,punchagan/zulip,synicalsyntax/zulip,eeshangarg/zulip,amanharitsh123/zulip,timabbott/zulip,kou/zulip