Fix treatment of reference properties in yml parser

See merge request caosdb/caosdb-advanced-user-tools!88

f xlsimporter error

Closes #52

See merge request !16

When importing a table using the TableImporter, it is now possible to
use the enum_converter to assure that values are part of a supplied enum.

FIX: treat lists of base datatypes properly during yaml model parsing

See merge request caosdb/caosdb-advanced-user-tools!81

F fix list

See merge request !14

f move test

See merge request !17

Improved the handling of numpy scalars in cfoods.h5.h5_attr_to_property

See merge request caosdb/caosdb-advanced-user-tools!84

f inspect xfail

See merge request !15

 to the corresponding issues

Improved the handling of numpy scalars (whether bare or 0-dimensional ndarrays) in cfoods.h5.h5_attr_to_property.

F yaml documentation

See merge request !10

F safe inttest

See merge request !12

The integration tests delete all data in a CaosDB server. This is now displayed again in a question before starting the tests.