[FEATURE] New landing page

[FIX] strong text and link ripple charts

[FIX] SVG logo

[FIX] update gateway logos and XRP hero with SVGs

[FIX] only show new sections if not logged in

[FEATURE] add ng-class to new landing wrapper

[FEATURE] add loggedOut check and class

[FIX] adjust indentation for login

[FEATURE] add loggedOut status and interior nav

[FIX] updated nav colors

[FIX] padding and color adjustments

[FEATURE] Updates for landing page

-Changed main hero graphic and welcome text
-Adjusted nav colors and subnav dropdown
-Removed icons from nav (mobile as well)
-Centered active ‘carat’ for main nav items
-Added links to gateways
-Updated to use ‘mixedCase’ for naming styles
-Removed <strong> tags from Jade and updated styles
-Removed unnecessary ‘ticker’ section
-Updated main logo to be a background image
-Changed @lightgray variable to match branding
-Code cleanup as per comments (2 spaces for indenting)
Merge pull request #1954 from ripplelabsben/landing-page

[FEATURE] Landing page