[TIMOB-6950] Ti API: UI - clipboard support for HTML

Request

Would be useful if Ti.UI.Clipboard supported copy/paste of HTML. There is a tutorial [here](http://mcmurrym.wordpress.com/2010/08/13/pasting-simplehtml-into-the-mail-app-ios/) on how to do it.

Usecase

Let's say I'm building a scrapbook app where people can save various memories, text, pictures. I want them to be able to save part of emails/webpages, etc... The problem now is that Titanium doesn't support HTML in the clipboard, so it's pasted as plain text. The user want to save the whole part of an email/website, not just the text, but the formatting too. The following methods would solve this:

.getHTML()
.setHTML()
.hasHTML()

Test case

Testcase for when it's implemented:

var c = Ti.UI.Clipboard;

c.setHTML('<b>test</b>');

var win = Ti.UI.createWindow();

var webView = Ti.UI.createWebView({
	html: c.hasHTML() ? c.getHTML() : c.getText()
});

win.add(webView);

win.open();