Update POM version numbers to 5.1.0-m1
Update auto-generated documentation

Repository: openmicroscopy/bioformats
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Generated by BIOFORMATS-5.1-latest-docs-autogen#139 (http://ci.openmicroscopy.org/job/BIOFORMATS-5.1-latest-docs-autogen/139/)
Merge pull request #1327 from snoopycrimecop/develop/latest/autogen

Update auto-generated documentation
Merge pull request #1325 from melissalinkert/5.1.0-m1-version

Update POM version numbers to 5.1.0-m1
cpp: Add FormatWriter
cpp: FormatReader: Drop metadata being string only comment