Ability to change instance name

As an Owner I'd like to set instance name so that it represents my resource

Acceptance Criteria

• Admin user should have Administration menu item at the top bar near its username. There should be a sub-menu Admin Mode.
• After entering Admin Mode, instead of previous Admin Mode menu item he should see Exit Admin Mode
• If user is in Admin Mode, when hovering the instance name at the top left corner, he should see a pen which would mean that it is editable.
• Then if user presses on the instance name, he should see an input right in place where he can enter the instance name.
• Name applies after clicking on Enter
• If the input is left blank, then default instance name is written into DB. Default is: Antarcticle (right now it's JavaTalks Articles which is incorrect)
• Max title length - 256.
• If title is too long and doesn't fit the bar, the end should be cut and '…' should be shown