Add `_` to some term constants for consistency.

Terms changed:
`CONCATMAP`
`ORDERBY`
`TYPEOF`
`FUNCALL`
`FOREACH`
`GEOJSON`
`TO_GEOJSON`
Revert change to `GEOJSON` terms.
Reverse method aliases in `func.rb` to maintain old methods.
Revert change to `FUNCALL` term.
Fix race condition in mailbox destruction by making mailbox_t destructor block until all callbacks have finished. Mailbox callbacks now take an interruptor signal that is pulsed when the mailbox_t is destroyed.
Catch interrupted_exc_t thrown by mailbox callbacks.
Add clarifying comment.
Merge pull request #3169 from grandquista/next

Encode connection authorization key once.
Used a static_cast to explicitly convert an optional to bool in reactor_be_primary.cc.
Fixed linker error with boost::optional operator<< symbol not being found.
Merge branch 'sam_osx' into next
Catch exception by const reference
merge of #3150 rename the parameters to `eq_test` in `test/rql_test/drivers/driver.rb`
merge of #2998 Python connection test failures
fixed a merge error
Merge branch 'tim_mailbox_destructor_race' into next
stash
encode web assets into C++
Got static web assets to work
python 3 compatible weba ssets script