Fix writing of tiff description

toCharArray() is the same as getBytes('UTF-16BE')
This leads to have unicode for units not being
correctly encoded.
Add test checking that the reader used is the OME-TIFF reader.
Add doc.
Merge pull request #1459 from jburel/encoding

Fix writing of tiff description
Update auto-generated documentation

Repository: openmicroscopy/bioformats
Already up-to-date.

Generated by BIOFORMATS-5.1-latest-docs-autogen#221 (http://ci.openmicroscopy.org/job/BIOFORMATS-5.1-latest-docs-autogen/221/)