Channel as int

To test the PR
 * Import a dv
 * go to the Acquisition tab
 * Expand a channel. 
 * Check that the emission/excitation wavelength are  displayed as int e.g. 450 instead of 450.0
Oughtn't this be an integer? In the UI I am getting,
![wavelengths](https://cloud.githubusercontent.com/assets/2630707/4502918/78cb4da4-4ad0-11e4-8479-535e80bddca7.png)