Use high-res image for Linux Foundation header

[pfmooney]

Unlike the rest of the images on the site, the Linux Foundation header is neither SVG nor high resolution. On high DPI screens, it looks poor compared to the rest of the content.

[fhemberger]

Yes, I'm not happy with the header either as it doesn't really look good on mobile as well.

EDIT: Found one version in higher resolution: http://collabprojects.linuxfoundation.org/sites/all/themes/lfcollab/images/lfcollab_logo.png

[pfmooney]

Perhaps they can be reached for a vector version.

[indexzero]

@pfmooney @fhemberger if we can get the fonts used then we can make our own vector of it.

[snostorm]

As another backup source, http://collabprojects.linuxfoundation.org/sites/collabprojects/files/lf_collaborative_projects_brochure.pdf has a vector version embedded

[pfmooney]

Looks great. Thanks @fhemberger.