Fix some tests and docs, little code fix up.

Fix some tests and docs. Add ability to run one test file with help gulp task.

Signed-off-by: Oleksandr Andriienko <oandriie@redhat.com>

src/Viewport.ts

@@ -20,7 +20,7 @@ export class Viewport {
    * @param terminal The terminal this viewport belongs to.
    * @param viewportElement The DOM element acting as the viewport.
    * @param scrollArea The DOM element acting as the scroll area.
-   * @param charMeasureElement A DOM element used to measure the character size of. the terminal.
+   * @param charMeasure A DOM element used to measure the character size of. the terminal.
    */
   constructor(
     private terminal: ITerminal,
@@ -43,8 +43,6 @@ export class Viewport {
   /**
    * Refreshes row height, setting line-height, viewport height and scroll area height if
    * necessary.
-   * @param charSize A character size measurement bounding rect object, if it doesn't exist it will
-   *   be created.
    */
   private refresh(): void {
     if (this.charMeasure.height > 0) {