#3155: Replace register text with svg in 'HeaderMenu'

[jeff1evesque]

Resolves #3155.

[coveralls]

Coverage remained the same at 53.433% when pulling 463ec34 on feature-3155 into 12e249e on master.

[coveralls]

Coverage remained the same at 53.433% when pulling 463ec34 on feature-3155 into 12e249e on master.

[coveralls]

Coverage remained the same at 53.433% when pulling 463ec34 on feature-3155 into 12e249e on master.

[jeff1evesque]

The following is the anonymous mobile view:

[coveralls]

Coverage remained the same at 53.433% when pulling 9e308c9 on feature-3155 into 12e249e on master.

[jeff1evesque]

We have some syntax errors across various of our linters. However, we'll continue to merge this issue, and implement granular commits, to see if each fix iteration will return a failed exit code to travis, within #3159.