Set draggable attribute to a true/false bool, and remove t/f/a set

…auto isn’t a valid value for draggable. true/false/auto isn’t needed
once that uses a boolean.

src/vs/languages/html/common/htmlTags.ts

@@ -146,7 +146,7 @@ export function getHTML5TagProvider(): IHTMLTagProvider {
 		'aria-describedby', 'aria-disabled:b', 'aria-dropeffect:dropeffect', 'aria-errormessage', 'aria-expanded:u', 'aria-flowto', 'aria-grabbed:u', 'aria-haspopup:b', 'aria-hidden:b', 'aria-invalid:invalid', 'aria-kbdshortcuts',
 		'aria-label', 'aria-labelledby', 'aria-level', 'aria-live:live', 'aria-modal:b', 'aria-multiline:b', 'aria-multiselectable:b', 'aria-orientation:orientation', 'aria-owns', 'aria-placeholder', 'aria-posinset', 'aria-pressed:tristate',
 		'aria-readonly:b','aria-relevant:relevant', 'aria-required:b', 'aria-roledescription', 'aria-rowcount', 'aria-rowindex', 'aria-rowspan', 'aria-selected:u', 'aria-setsize', 'aria-sort:sort', 'aria-valuemax', 'aria-valuemin', 'aria-valuenow', 'aria-valuetext',
-		'accesskey', 'class', 'contenteditable:b', 'contextmenu', 'dir:d', 'draggable:a', 'dropzone', 'hidden:v', 'id', 'itemid', 'itemprop', 'itemref', 'itemscope:v', 'itemtype', 'lang', 'role:roles', 'spellcheck:b', 'style', 'tabindex',
+		'accesskey', 'class', 'contenteditable:b', 'contextmenu', 'dir:d', 'draggable:b', 'dropzone', 'hidden:v', 'id', 'itemid', 'itemprop', 'itemref', 'itemscope:v', 'itemtype', 'lang', 'role:roles', 'spellcheck:b', 'style', 'tabindex',
 		'title', 'translate'];
 
 	var eventHandlers = ['onabort', 'onblur', 'oncanplay', 'oncanplaythrough', 'onchange', 'onclick', 'oncontextmenu', 'ondblclick', 'ondrag', 'ondragend', 'ondragenter', 'ondragleave', 'ondragover', 'ondragstart',
@@ -156,7 +156,6 @@ export function getHTML5TagProvider(): IHTMLTagProvider {
 
 	var valueSets : { [tag:string]: string[]} = {
 		b: ['true', 'false'],
-		a: ['true', 'false', 'auto'],
 		u: ['true', 'false', 'undefined'],
 		d: ['ltr', 'rtl', 'auto'],
 		m: ['get', 'post'],