Video options on browser

Hi, I need to get high resolution images in my browser app. The implementation on this package of getUserMedia looks like this:

```
// initiate request for webcam
navigator.getUserMedia({
video: true,
audio: false
}, success, failure);
```

This is always making my cam take pictures on low resolution... is this the correct way of telling getUserMedia to get high resolution images?

```
// initiate request for webcam
navigator.getUserMedia({
video: mandatory:{
minWidth:1280
minHeight720,
},
audio: false
}, success, failure);
```

If it is, shouldn't this be an option to pass in 'options' when calling MeteorCamera.getPicture? the width and height you pass on options only tell the size of the canvas, not the resolution of image, am I right ?

Start with the MeteorCamera.getPicture entry point and compare its options with the navigator.getUserMedia video constraints shown in the issue. Check how the existing width and height options affect the canvas, then determine whether camera resolution constraints can be passed through; done means high-resolution captures can be requested without changing only the canvas size.

Written by the indexing model from the issue text.