Unify format of descriptor maps (or not)

[perellonieto]

The localisation and activity examples use different format of descriptor_map

eg. The localisation uses arrays of integers denoting the labels

bHealth/examples/localisation_example.py

Lines 100 to 105 in 73bd95f

	descriptor_map = {
	'foyer' : [0],
	'bedroom' : [1],
	'living_room' : [2],
	'bathroom' : [3]
	}

While the accelerometer example uses integers

bHealth/examples/accelerometer_example.py

Lines 114 to 121 in 73bd95f

	descriptor_map = {
	'sitting' : 77,
	'walking' : 78,
	'washing' : 79,
	'eating' : 80,
	'sleeping': 81,
	'studying': 82
	}

What is the reasoning behind it, and which method should we choose as standard. A benefit from the list is that it could group labels, for example "upstairs" could be associated to [0, 1, 2], or "sedentary" as well.

I am not sure if there are collateral implications on this modification.

[rymc]

I quite like the idea of a list. It is little less clear in terms of an accelerometer - but the added flexibility may be useful if you want to, for example, group running, swimming, frisbee, basketball all as 'exercise'.