Schneesturm-Effekt 1.4.0

ADD: new snow flake system (nextapps-de)
ADD: optional seasonal schedule window (start/end date) for public snow rendering
ADD: display scope option (everywhere, homepage only, selected forums only, everywhere except selected forums)
ADD: forum include/exclude selectors for scope targeting
ADD: templater_setup listener + wutime_snowstorm_is_mobile() template helper
ADD: Detection\MobileDetect composer package for server-side mobile detection
ADD: admin-only preview checkbox to render selected theme on SnowStorm options page for quick testing

FIX: Disabling snowstorm effects from account preferences is now visible in XF 2.3.x

UPDATE: light-weight snow to v0.0.4 for compatability with XF 2.3x, document.write() and defer
ADD: link and create proper minified JS for production systems
UPDATE: build.json for updated *.min.js using UglifyJs
ADD: font-awesome 5 igloo icon to option group