Giving up Clang, ns tools, login direct to Heritage, Invite featuring

Added namespace tools to enable (refresh) when some files are not refreshed, e.g.
After logging in with facebook, now the user is redirected to his account.
Removed 'src/app/views/login.clj' because it’s being redirected to fn in ‘heritage.clj'.
Limboed ‘src-cljs/app/clang.cljs’. Giving up on Clang because it’s not working.
Implemented listen-pairs! in ‘app.core’.
Implemented show-div! to DRY toggle!.
Implemented invite feature structure.
Merge branch 'master' of https://github.com/ccfontes/bitdigger
Self licking ice cream changes

Implemented some parts of the Stuart Sierra Workflow. To reload everything after changes, type (reset) on the REPL.
Fixed post-merge for cljs. (I think - seeing will be believing)
Removed (monger/disconnect!) from tests because it disconnects the app DB connection. Maybe it’s not important not to disconnect. This issue (#277) was reported in midje.