Don't permit object-like operations on ptypes
Thread checks in where it makes sense.
Test merge arguments too
Insert checks for merge arguments
Test path arguments
Per @mlucy, standardize error message & implementation
Bump reql_version_t

v1.16 introduces changes in operations on pseudotypes.
Only do checks for v1.16

This should address some of the sindex problems; at least we use the
old behavior.  Not sure how to proceed with warnings.
fix merging of r.http depage params
adding a message to an assert about resunder
Remove switch and replace with statement.

The existence for the switch statement is some dimly remembered "we
might have more complicated logic some day" assesment.  We don't.
When we do have more complicated logic, we can put it back in, but
until that day it just confuses things.
Per @tryneus, improve backtrace targets.
Verify better error message with test.
Target right object
Merge branch 'gchpaco_2766' into next

Fixes #2766.  This isn't a good idea to put in 1.15, so it is only going to next.
adding resuming of incomplete vectored disk i/o
adding __getinitargs__ to RqlTzinfo so it can be pickled/unpickled
Fix the geometry related breakage

@mlucy wanted me to move the check into obj_or_seq_op_term_t, but none
of us checked that all consumers of that shouldn’t consume ptypes.
Fix temporary leakage here

@Tryneus caught leakage of a temporary here.

This and its parent were approved in CR 2144.
Handle LITERALs specially in `merge`

This is more breakage from the `ptype` stuff.

Over the shoulder from @mlucy.