Fix for #85
Fix #82
Update README.md

Mark Security Roles overview as done
Update INSTALL_Centos.md

Fixed a couple of typos and made a couple of instructions clearer. I believe step 5 (updating SDE) needs updating but couldn't remember the correct steps.
Merge pull request #91 from Nutbolt52/patch-1

Update INSTALL_Centos.md
Update INSTALL_Centos.md

Add version hint
Convert from using Auth to Sentry, with a first pass at adding permissions to sidebar and key management