A few details in the makefile and in the manual. (In particular,
it updates the dependency lists in the makefile.)

This file is not part of the regular tests. It tests error conditions
that demand too much memory or too much time to create:

* string with too many characters
* control structure with body too large
* chunk with too many lines
* identifier with too many characters
* chunks with too many instructions
* function with too many constants
* too many strings internalized
* table with too many entries

In machines with limited memory (less than 150 GB), many tests run up
to a "not enough memory" error. We need some memory (~256 GB) to
run all tests up to their intrinsic limits.

A long bracket with too many equal signs can overflow the 'int' used for
the counting and some arithmetic done on the value. Changing the counter
to 'size_t' avoids that. (Because what is counted goes to a buffer, an
overflow in the counter will first raise a buffer-overflow error.)

New functions to reset/kill a thread/coroutine, mainly (only?) to
close any pending to-be-closed variable. ('lua_resetthread' also
allows a thread to be reused...)

- in 'luaB_tonumber', do not need to "checkany" when argument
is a number.

- in 'lua_resume', the call to 'luaD_rawrunprotected' cannot return
a status equal to -1.

The call 'math.rand()' converts the higher bits of the internal unsigned
integer random to a float, instead of its lower bits. That ensures that
Lua compiled with different float precisions always generates equal (up
to the available precision) random numbers when given the same seed.

New auxiliary functions/macros 'luaL_argexpected'/'luaL_typeerror'
ease the creation of error messages such as

  bad argument #2 to 'setmetatable' (nil or table expected, got boolean)

(The novelty being the "got boolean" part...)

A to-be-closed variable must be closed when a block ends, so even
a 'return foo()' cannot directly returns the results of 'foo'; the
function must close the scope before returning.

It is an error for a to-be-closed variable to have a non-closable
non-nil value when it is being closed. This situation does not seem to
be useful and often hints to an error. (Particularly in the C API, it is
easy to change a to-be-closed index by mistake.)

To remove a to-be-closed variable from the stack in the C API a
function must use 'lua_settop' or 'lua_pop'. Previous implementation of
'luaL_pushresult' was not closing the box. (This commit also added
tests to check that box is being closed "as soon as possible".)