add baseurl for serving from personal git repo

this change should NOT be merged into organization repo or the any branches other than 'gh-pages' on personal repo.\nThus NO Pull Request should be made from personal 'gh-pages' branch to the organization repo.
Merge branch 'mobile' into gh-pages
To apply mobile updates to 'gh-pages' without removing updates previously made to 'gh-pages'
Merge branch 'logo' into gh-pages
Merge branch 'analytics' into gh-pages
Merge branch 'logo' into gh-pages
Merge branch 'master' into gh-pages
Merge branch 'master' into gh-pages
- changed participate form back to use select
- for better ux on mobile devices (iOS)
- fixed styles and validation issues
- update form multiselect style height
update participate for on gh-pages to navigate correctly to 'thanks' page
update logo path on 'gh-pages' branch to navigate correctly to 'site.baseurl'
added sponsors tab
removed baseurl inherited from gh-pages