Adding in link to HipChat help doc explaining who can access 1-1 history and under what circumstances

Hey thanks for the great write-up on HipChat vs the competition.  I know a lot of people were upset about the TOS changes which on the surface sound pretty scary, but the reality is much less Big Brother and much more about offering admin access to those who want it not adding it for all.  Check out the help article which explains all the details.  Full disclosure, I work for Atlassian on the HipChat team :-)