function parseSpeed(value)
	{
	    if(value in speeds)
	    {
	        value = speeds[value];
	    }

	    value = parseFloat(value);
	    if(isNaN(value) || !value || value <= 0)
	    {
	        value = 1;
	    }
	    return value;
	}
accept a speed name shortcuts or a number and give back an acceptable positive value.
Fallback to 1 if value is out of valid range

@param {string|number} value
@returns {number}