switches to the configured display name for circle avatars

[gerbenjacobs]

Switches the letter in the circle avatars (if not using custom avatars) to be taken from the configured display name (which is name by default)

Not only will this then match with the name of the author, it also prevents a bit of a privacy issue when the e-mailaddress first letter doesn't match with the author name.

In this merge request I also

• added a space between all emoticons/images and text for readability
• fixed a html error in the mail template

Change-Id: I5182e1c0664326ede089fa857dcb391edb20f088

[marktopper]

Thanks 👍