ActivityStream shows events of today two hours too early

The ActivityStream shows Events of today somewhat two hours later than when they actually happend.

Steps to reproduce:

• create some event, e.g. by adding a message, create a page ...
• look at /Main/Activity - the event is visible as "less than one hour ago" (which is actually correct, but the code suggests it should say "a few seconds ago")
• now wait for one hour (or change the event date in the DB directly); the event is still listed as "less than one hour ago" although it is actually more than one hour ago
• wait for e.g. two hours 15 minutes (or, again, change the ase_date in the DB); activity stream now says it is "15 minutes ago".

Looking at the "title" attribute for that text one can see the date arrived correctly, but the time difference calculation is created wrong.

It seems someone thought it necessary to subtract two hours hard wired when calculating the time difference. Whatever that might have helped with, I feel hard wiring this value of '2' is propably wrong. Additionally the issue described here goes away if this subtraction is dropped.

I will try to send a pull request shortly.