logging

[ddale]

improve logging throughout the library, converting print statements to logger calls

• xrd.spotfinder
• xrd.transforms_CAPI
• xrd.transforms
• xrd.xrdutil
• xrd.spacegroup
• xrd.rotations
• xrd.material
• xrd.indexer
• xrd.hydra
• xrd.grain
• xrd.fitting
• xrd.experiment
• xrd.distortion
• xrd.detector
• xrd.crystallography
• valunits
• tens
• plotwrap
• orientations
• fileutil
• coreutil
• arrayutil