Update the manual and the configuration file
to reflect the new WAL writer architecture.

https://bugs.launchpad.net/tarantool/+bug/837484

default src configuration files path changed to test/share/

'find' TreeIndex class member was fixed. Now allocate enough space for key_data.

Conflicts:
	mod/box/index.h
	mod/box/index.m
	mod/box/tree.m
	test/box/lua.result
	test/box/lua.test
	test/box_big/tarantool.cfg

As part of the merge, revers int -> u32
type change for key_cardinality, done in the
blueprint-multipart-primary-key branch (didn't
notice during code review, but it breaks
formatting in errcode.h).

Merge new and old tests in box_big
manually.

Spelling fixes in the error message file.

Add more information to the error when key cardinality
doesn't match index cardinality in exact match.

Avoid server start/stop in box_big/hash.test (ugly,
but until we have named/dynamic spaces, which are already in the
pipeline, we should not make our test procedure slower).

Rename multipart-pk.test to tree_pk_multipar.test:
consistently use underscores, not dashes, in file
names.

(Unrelated) Recycle more error codes.

Make keyValue an inline function to save a few CPU cycles.

Avoid creation of an extra table in box.lua just to find out
variable list array cardinality.

Revert changes to box.update():
a) they break backward compatibility

This reason alone should be sufficient. There must be no changes
which break backward compatibility in a stable release, unless
it's a fix for a crashing/security bug.

box.update() changes got to be done in a separate task,
and should not break backward compatibility.

Leave update_ol for now, to test multi-part primary key updates,
even though the function itself is quite heavy, hardly something
we can recommend while running Lua procedures in production.

Warnings was removed. Minor coding-style cleanup.