changes (not incompatibilities) to Lua 5.0 beta

[Roberto Ierusalimschy <roberto@...>]

Here is a list of novelties in 5.0 beta (compared to 5.0 alpha). They
should create no incompatibilities in "normal" programs.

* The compiler does not change the order of operands for "commutative"
operators. (I don't remember why, but I remember there was quite a
discussion about that in the list.) (However, "a>b" is still translated
to "b<a", and "a>=b" to "b<=a".)

* new facility to precompile Lua code from inside Lua (function
stringdump).

* option "-l" in lua.c does a "require" (and therefore searches
LUA_PATH), instead of a simple dofile.

* reorganization of object headers plus macros/documentation towards an
incremental garbage collector. We plan to have the incremental collector
in 5.1 (to be released as soon as possible, but only after 5.0 ;-).

* support for yields inside line/count hooks.

-- Roberto