Micro Blogs UI
**Attention:** This MR includes several other commits which are supposed to end up in separate MRs. I suggest that you review **per commit**. Once the first two commits have green light, I can split out the other commits into other MRs. This way I don't have to work myself through a long rebase chain every time I make a change to the bottom MR.
This MR is full of commits that introduce features that we will not be using initially. The last commit implements the Micro Blogs UI on top of the framework the first commits establish and hides/disables all future features for now.
I suggest we merge this as is and clean things up later when we have a clearer idea what features we will be doing eventually.
Closes#436
See merge request !214
Clicking the plus in the toolbar open the `CreateBlogActivity` which
allows the user to create a new blog. Only the first identity is
considered, but support for more identities can be easily added later.
The actual list of blogs in the My Blogs tab will be done in the next
commit.
