Add documentation of server foregrounding.

@mtbc was not aware of the existence of the --foreground
option. Hence it makes sense to expose it in the docs.
merge dev_5_0 -D org: PR 918 (Update auto-generated properties)
merge dev_5_0 -D org: PR 921 ( DropBox configuration clarification)
merge dev_5_0 -D org: PR 924 (Add documentation of server foregrounding.)
merge dev_5_0 -D org

Repository: openmicroscopy/ome-documentation
Excluded PRs:
  # PR 899 rleigh-dundee 'Cpp: Document building with cmake (dev_5_0)' (exclude comment)
Already up-to-date.

Merged PRs:
  # PR 918 sbesson 'Update auto-generated properties'
  # PR 921 ximenesuk ' DropBox configuration clarification'
  # PR 924 bpindelski 'Add documentation of server foregrounding.'

Generated by OME-5.0-merge-push#155 (http://ci.openmicroscopy.org/job/OME-5.0-merge-push/155/)