A recent branding effort exposed several aspects of the header
templates that need to be more composable to enable richer
customizations.
The Horizon _header.html template has many components within it:
region pickers, user menus, logos. All of these things are highly
desirable to customize, but because it is all contained in the same
template, a brander will have to override the entire template. This
is not ideal as it increase the cost of maintenance.
The splash section of the login page, the context selector, the logo
section of the header, the user menu and the region selector are now
composable to a much more granular level. The top navigation menus
can now be used outside of existing within a list. The templates
now allow use as normal, standalone dropdown items.
Also, the current primary color used for 'material' was highly
unpleasant with OpenStack Red. Another color on the material design
palette was chosen, very close to the previous blue. See
https://www.google.com/design/spec/style/color.html#color-color-palette
To showcase this new composability, 'material' now shows how to
customize the logo and logo-splash beyond just replacing the png, but
now allowing the use of any type of image. In this case, the
OpenStack logos have been upgraded with their svg counterparts.
It was also noted that the context selection menu was using the wrong
variable to set the color of its links. This was corrected.
Closes-Bug: #1518584
Change-Id: Ib544176b9836e17fc913170664646e1d10eda831
378623217d