[TIMOB-2975] iOS: Scroll end view consistency / parity with Android

The iOS implementation of the 'scrollEnd' event fires the event when the user lifts their finger. Our docs state: "fired when the table view stops scrolling (currently, iphone only)". Whether that should happen upon deceleration or another way is not clear. Either way, it doesn't currently fire the way the documentation leads.

Also, the event is named 'scrollEnd' (camelcase) which is not consistent with most of our other event names.

This is a ticket that is in line with the Android ticket here: https://appcelerator.lighthouseapp.com/projects/32238/tickets/2622-android-add-scroll-end-event-to-scroll-views"> https://appcelerator.lighthouseapp.com/projects/32238/tickets/2622-...

HD ticket here: http://developer.appcelerator.com/helpdesk/view/69201">http://developer.appcelerator.com/helpdesk/view/69201

Sample:

var win = Ti.UI.currentWindow; 
win.backgroundColor = '#fff';

var rows = [];

for (var i = 0; i < 1000; i++) {
    var row = Ti.UI.createTableViewRow();
    
    var label = Ti.UI.createLabel({
        text: 'Some label ' + i
    });
    row.add(label);
    
    rows.push(row);
};

var table = Ti.UI.createTableView({
    data: rows
});

table.addEventListener('scroll', function(e) {
    //Ti.API.info('Start ' + e);
});

table.addEventListener('scrollEnd', function(e) {
    Ti.API.info('End ' + e);
});

win.add(table);