cpp: Adapt to Boost 1.56 optional changes

- Explictly dereference optional values
- Use double negative for comparing to true
Correct Time comparison in tests

Correcting problem found by findbugs
Merge pull request #1370 from rleigh-dundee/cpp-optional-fix

cpp: Adapt to Boost 1.56 optional changes
merge develop -Dnone -Ibreaking -Eexclude -Ssuccess-only: PR 1265 (New units)
merge develop -Dnone -Ibreaking -Eexclude -Ssuccess-only: PR 1362 (Make FormatReader's RandomAccessInputStream transient)
merge develop -Dnone -Ibreaking -Eexclude -Ssuccess-only

Repository: openmicroscopy/bioformats
Excluded PRs:
  # PR 1015 qidane 'Messy binary' (exclude comment)
  # PR 1366 ctrueden 'Miscellaneous cleanup' (user: ctrueden)
  # PR 1161 sommerc 'Initial CellH5 Reader class' (user: sommerc)
  # PR 857 melissalinkert 'Initial support for Zeiss .lms files' (user: melissalinkert)
  # PR 1369 sbesson 'Document usage of setSeries() and getIndex() in MATLAB documentation' (user: sbesson)
  # PR 1177 rleigh-dundee 'specification: Add metadata for HDF5 embedding' (exclude comment)
  # PR 1309 melissalinkert 'Allow tile-based access of large JPEG-2000 images' (exclude comment)
  # PR 1365 ctrueden 'PrairieView 5.2 fixes and improvements' (user: ctrueden)
  # PR 858 melissalinkert 'Initial support for Veeco AFM data' (user: melissalinkert)
  # PR 1296 melissalinkert 'Add test for getRequiredDirectories' (user: melissalinkert)
Updating 5706a61..0a9eb25
Previously merged:
  # PR 1370 rleigh-dundee 'cpp: Adapt to Boost 1.56 optional changes'

Merged PRs:
  # PR 1265 qidane 'New units'
  # PR 1362 melissalinkert 'Make FormatReader's RandomAccessInputStream transient'

Generated by OME-5.1-breaking-push#123 (http://ci.openmicroscopy.org/job/OME-5.1-breaking-push/123/)