FLUID-5378: Updating the docs for release

Updated the README and ReleaseNotes for the Infusion 1.5 release.
Merge branch 'master' into FLUID-5378
FLUID-5378: Updated based on review
FLUID-5378: A few more corrections.

Removed an extra word from the README, and adjusted the tested browsers.
Merge remote-tracking branch 'jobara/FLUID-5378'

* jobara/FLUID-5378:
  FLUID-5378: A few more corrections.
  FLUID-5378: Updated based on review
  FLUID-5378: Updating the docs for release