Add `_` to some term constants for consistency.

Terms changed:
`CONCATMAP`
`ORDERBY`
`TYPEOF`
`FUNCALL`
`FOREACH`
`GEOJSON`
`TO_GEOJSON`
First draft of .
Fix bugs in watchable_map_t. Add a new type of directory manager that uses a watchable_map_t instead of a single watchable_t.
Mostly converted reactor to use watchable_map_t instead of watchable_t, but it doesn't build yet.
Revert change to `GEOJSON` terms.
Reverse method aliases in `func.rb` to maintain old methods.
Revert change to `FUNCALL` term.
watchable_map_t conversion now builds, but has bugs.
Unit tests pass now.
Merge branch 'reql_admin' into tim_map_watchable

Conflicts:
	src/clustering/administration/artificial_reql_cluster_interface.cc
	src/clustering/administration/artificial_reql_cluster_interface.hpp
	src/clustering/administration/main/serve.cc
	src/clustering/administration/metadata.cc
Make it compile on GCC.
Compile on GCC 4.6.3.
Re-introduce buffering of directory changes to hopefully improve performance.
Updated workload X to work again (and updated the README)
Fixes cpplint errors, over the shoulder review by @larkost
Fix #3173.
Merge branch 'daniel_workload_x_fixes' into next
Adds a range operator that generates all the numbers in a certain range
Fixes review feedback
Fixes one more reivew comment