minor doc tweaks
minor adjustments to system configuration

includes,
* link to memory settings configuration
* removal of OpenGL clients (coming real soon)
explain more about the binary repository
reorder lists of operating systems to promote Linux

suggested by @manics
reword sentence to remove active voice

suggested by @bpindelski
merge dev_5_0 -Dorg -Ssuccess-only: PR 951 (improve and update server configuration documentation (rebased from develop))
merge dev_5_0 -Dorg -Ssuccess-only

Repository: openmicroscopy/ome-documentation
Excluded PRs:
  # PR 952 hflynn 'Adding OMERO version history to docs (rebased onto dev_5_0)' (status: error)
Already up-to-date.

Merged PRs:
  # PR 951 mtbc 'improve and update server configuration documentation (rebased from develop)'

Generated by OME-5.0-merge-push#190 (http://ci.openmicroscopy.org/job/OME-5.0-merge-push/190/)