fix(tpl): switch login/signup to profile/logout when logged in

[ZacharyRSmith]

Notes

resolves #18

Testing

ran locally, then:

• logged in as system
• asserted avatar shows up
• asserted log out changes ui

[themightychris]

@ZacharyRSmith looks great! One small issue with this current implementation is that we're overriding the same html-templates/includes/site.nav-userlinks.tpl that the non-bootstrap4 pages use, so they look funky now because they don't have the right classes for bootstrap3:

I think we'll need to give the bs4 variant its own path so it can co-exist with the bs3 one for now. So rename site.nav-userlinks.tpl to something like site-bootstrap4.nav-userlinks.tpl and update the {include} that references it in site-bootstrap4.tpl and I think we're good to go!

[ZacharyRSmith]

@themightychris thanks for catching that! I just fixed it, tested locally, then pushed to this PR

[themightychris]

@ZacharyRSmith looks great, thanks!