fix: position, lineAlign, positionAlign (#36)

Also, increase backwards compatibility and compatibility with native vttcue implementations.

lib/vtt.js

@@ -561,16 +561,16 @@ function StyleBox() {
 StyleBox.prototype.applyStyles = function(styles, div, inlineStyles, onapplystyles) {
   div = div || this.div;
 
-  if (inlineStyles) {
+  if (this.inlineStyles) {
     for (var prop in styles) {
       if (styles.hasOwnProperty(prop)) {
         div.style[prop] = styles[prop];
       }
     }
-  } else {
-    if (typeof onapplyStyles === 'function') {
-      onapplystyles(styles, div);
-    }
+  }
+
+  if (typeof this.onapplystyles === 'function') {
+    this.onapplystyles(styles, div);
   }
 };
 
@@ -583,6 +583,8 @@ StyleBox.prototype.formatStyle = function(val, unit) {
 function CueStyleBox(window, cue, styleOptions, inlineStyles, onapplystyles) {
   StyleBox.call(this);
   this.cue = cue;
+  this.inlineStyles = inlineStyles;
+  this.onapplystyles = onapplystyles;
 
   // Parse our cue's text into a DOM tree rooted at 'cueDiv'. This div will
   // have inline positioning and will function as the cue background box.