Improved looping; safely mutate listeners queue

[crazy4groovy]

Admittedly I can't run the tests on my Windows machine :( So take this PR with a grain of salt.

npm-run-all --silent -p build:main build:integrations build:combined -s size docs

Error: ENOENT: no such file or directory, open 'D:\dev\projects\unistore\src\integrations*.js' Error: ENOENT: no such file or directory, open 'D:\dev\projects\unistore\src\combined*.js' Build output to dist: 554 B: unistore.es.js 323 B: unistore.js 391 B: unistore.umd.js 325 B ERROR There is no matching file for full/preact.js in D:\dev\projects\unistore

Cheers