Use the unique position coordinate count as backup method of setting the position count
Improved metadata parsing

Channel names, emission wavelengths, exposure times, and physical
positions are now more completely recorded in MetadataStore.
Revert usage of addGlobalMetaList
Fix one more issue with setting the channel color
Use the unique Z position count as a last resort to determine the series count
Account for stage drift when counting unique Z positions
Moderate setId and openBytes performance improvements
Prevent seeking beyond the end of the file
One more set of performance changes

Reduces the number of skips, and removes System.arraycopy when a very
small number of bytes are being copied.
Replace erroneous call to addGlobalMetaList
One last removal of addGlobalMetaList
Fix dev_5_0-only compile error
Fix double => int wavelength parsing
Merge pull request #1275 from melissalinkert/nd2-5.0.4-dev_5_0

Performance and position count fixes for ND2