Focus on intuitiveness, efficiency and IE

Removed snap properties hard & onlyOnDrop in favour of snap.type; also snap.markers became snap.marks; added totalRange property & runtime values thereof returned; destroy method now chainable for jQuery; fixed minor scoping issue; modified colorShift handling; significant changes with regards to data entered and data received; replaced setInterval with event listener (+ IE polyfill); removed drag and drop callbacks from initiator function; added slider data to onload callback; jQuery: removed unnecessary removeEventListeners for IE that caused an error on destroy.