Characters for empty fields in the xma_metadata.xml file

[Elizabeth Brainerd]

There are no rigid bodies in the attached .xma file. The xma_metadata.xml file says: averageSD="0"

The Portal interprets this as zero, but instead it should be just empty since there are no pairwise intermarker distances.

Please put something else there. If they values will never be negative, it could be -1. Or NA or anything that Kia can read as empty.

Also for any other empty fields.

[Benjamin Knorlein]

fixes #137 : Reprojection error, average SD, first frame and last frame tracked are now written as NA, when there is no data available

→ <<cset 7bd12159fddc>>