Index page size and range size are storage-level properties
and can not change during index life time.
Initialize these properties from global defaults at index
creation time. This way they are not affected after restart
with different global options.

Remove "engine-level" options support from Lua, all options
are known to us now that we ditched third party engines.

Closes #1738

Closes #1737

g/static inline/statis is easier than merging an old branch
with a runaway trunk

ops

Do a proper roll back on dump/compact failure.

Now, names of related interfaces, global variables and
fields are based on "iterator".

This is pure refactoring without any functional changes.

Closes #1694

The range iterator open function used an obsolete indicator
for special key (NULL key), which led to selection of a wrong
range in :max() query.

The bug required a compaction process to trigger it, since
when there was only 1 range max() naturally always got the last one.
After compaction, range iterator open could yield a random
range for the special key.

Update errinj.test.lua to always trigger compaction.

Remove all ranges from scheduler before deleting index.

Follow up 43ca199e

The merge iterator didn't take into account iterator diretion
when merging its sources, and always used to return the smallest
tuple among the alternatives.

If iterator order is LT or LE, the biggest tuple should be returned
instead.

We don't remove dead index's ranges from the scheduler heap after we
scheduled a drop task for it - we only do it from the drop task itself.
As a result, we can happily go and schedule another task for the index
being already scheduled for destruction. This can result in the
index->ref == 1 assertion being violated in vy_task_drop_execute() or
memory corruption induced by use-after-free of a vy_index struct.

Switch to pointers from built-in structures range->i[01].

* add a test case based on error injection
* fix a few release mode warnings
* the test case is still failing, depends on introduction of shadow
memory indexes.

Use global queues for scheduling instead of per-index.

Fixes #1708

Update test run (fixes the sporadic console handshake bug when running
tests).

Fixes gh-1163.

Closes #1599

Don't access uninitialized memory in ev_io_closing().

anfds array is initialized with zeroes, when it's reallocated,
but anfdmax is array size, not array last element, so
anfds[anfdmax] is garbage.

When we're "closing" an fd which has never been added
to anfds (ev_io_start()) wasn't called for it), we
must check that it's within array size boundaries first.

Since range_id_max is not updated, indexes created after recovery might
get the same ids as recovered ones. If this happens, the next recovery
will crash, because there will be two or more identical ids in the range
index file.

Prepare for #1599

vy_range_redistribute() doesn't work correctly if ranges are not sorted
in ascending order.

vy_task_{dump,compact}_{execute,complete} serve as trivial wrappers for
the functions doing real work. Let's fold them to make the code more
straightforward. No functional changes intended.

While we touch this code, let's also get rid of all the pointless
unlikely's - after all the functions are not called from hot paths so
there's no point in cluttering the code.

This is pure refactoring, isn't supposed to introduce any functional
changes.