make header secontary style more generic and add to member show

adjust layout classes to make this work on member header
remove redundant references to social share and external links
update fixtures for previous 2 commits
remove unused external_links partial
make spacing of member photo more even (scss only)
stop bad wrapping of explainer links (scss only)
remove subscription class from speeches link
add speeches svg
styles for speech icon (scss only)
change speeches link icon to person at lecturn
fixture update for class changes
Merge branch 'master' into people_header_layout
make the speeches icon slightly less salient
add credit for speech icon to the readme
Remove extra, inconsistent full stop