fix link to Java Image I/O guide

current Bio-Formats minimum requirement is Java 6
Merge pull request #802 from mtbc/rebased/dev_4_4/java-imageio-link

fix link to Java Image I/O guide (rebased onto dev_4_4)
Update auto-generated documentation

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

Generated by BIOFORMATS-docs-autogen-stable#104 (http://hudson.openmicroscopy.org.uk/job/BIOFORMATS-docs-autogen-stable/104/)