Add help to most editable elements of a project

[cholmcc]

This patch help text to most editable elements in an project.

• Most editable elements that has a label associated with it, will
  have a "question" marker next to it. When the user hovers over
  that marker, they will see a short text describing the expected
  input.
• Other elements, such as edit buttons, or add buttons, will have
  tool-tip shown when the user hovers over it,
• Some input fields will also have a tool-tip text.

The point of this patch is to make the project editor more
self-explanatory, not least to accommodate those users that could not
be bothered to RTFM.

The aim is to clutter the interface the least possible, while at the
same time make the interface, and how to get help, as intuitive as
possible.

The patch also adds a Gallery header (with icon) if there any
images in the gallery or an owner is viewing the page.

The patch also adds help text to the new project page.

The Root page is also cleaned up a bit:

• The structure is illustrated by indenting the bullets
• A "Create new project" button has been added
• The text on migration has been removed because the task is no longer
  valid.
• The Do and Do Not text has been updated a bit (Do Not instead of the
  spoken-language Don't).

Screenshots:

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