fix BU3DFE connectivity, pretty JSON files

[jabooth]

Fix a slip up with the connectivity information on the bu3d_fe labeller. Luckily fixing any that we've made incorrectly is quite straightforward:

import menpo

def fix_bu3dfe_landmark(p):
    l = menpo.io.import_landmark_file(p)
    l_fixed = menpo.landmark.labels.bu3dfe_83(l)[1]
    menpo.io.export_landmark_file(l_fixed, p, overwrite=True)


from pathlib import Path

for lm in Path('./dir/of/bad/landmarks').glob('**/*.ljson'):
    fix_bu3dfe_landmark(lm)

I've also changed the landmark LJSON exporter to save out nicely formatted JSON rather than it all scrunched together which is helpful for diffing landmark changes. (landmarkerio server does the same style so diffs are not effected by ordering/style changes now)

[patricksnape]

FIne by me