chore(*): start of 4.0.1 hotfix work
[skip ci]
test(test/unit/templating.js): #1023 - getFileId for file template btns w/ varying hierarchies
fix(client/js/templating.js): fixes #1023 - file buttons more than one level deep can't be tied to their parent file container
fix(*): fixes #1021 - beforeUnload handler triggers confirm dialog unnecessarily
test(test/unit/templating.js): #1021 ensure fileId is a number
fix(client/js/templating.js): #1021 getFileId should return a number
Merge branch 'hotfix/4.0.1-button-issues'