working with django17
Lots of changes
migration in place
import export
import export
reload database changes

export
Better migrations and export
faster hierarchy reconstruction
clean export
Merge branch 'django17' of https://github.com/SamuelDeleglise/pyinstruments into django17
conflicts solved
right paths in export tests
unit tests OK
install doc
works in leo pc
explicit import of pyinstruments in datalogger was causing error at syncdb
bugfixes and version upgrade of pandas
picomotor driver added
PICOMOTOR works
script free_space created