Wrong start/end/duration times when switching regions.

[julj]

When switching from one region to another one, the start/end/duration times are wrong.
I guess this is due to the following lines

audio-annotator/static/js/src/wavesurfer.regions.js

Lines 206 to 208 in 02e8717

	this.updateRender();
	this.fireEvent('update');
	this.wavesurfer.fireEvent('region-updated', this);

during which the regions are not swapped (in swapRegion) until the end.