Some Problems with Tags and Markdown

As Day One uses Markdown for Stringformating, tags should be escaped.
I used the parentheses for the Slogger tags, because they are used by the other plugins too.
This does not make sense for the caption, so I used a space here.

I hope it is useful.
By the way, this is my first pull request on github, so please show me if I'm doing something wrong.

Patrick