Fixed the viewSession permissions.
Fix part of the bug (6392) reported in redmine:
Permissions not working properly. They should match Imaging Browser front page. Instead, anyone can see any page (This will be important when Imaging data is linked directly from a BVL-side timepoint page.
Fixed a typo in comments of hasAccess() function.
Merge pull request #785 from cmadjar/PermissionFixForImagingBrowser

Permission fix for imaging browser