Improvements Galore

chainable ($) • added jQuery 3 support ($) • added resize support • removed orientation-change event • removed showKnob to favour newly added noHandle • removed onload callback to favour ready event ($) or load method (standalone) • restored 'custom' property to output on ready • added Ctrl key option • added 2 more snap points (up to 11) • rebuilt snap marks • more accurate snapping • other minor snap improvements & bug fixes • removed CustomEvent polyfill • all callbacks now receive sGlide context (this) • removed internal custom element getter to favour querySelectorAll • better 'css' & 'extend' functions • refactoring and general bug fixes