changes in 'require'

[Roberto Ierusalimschy <roberto@...>]

We are trying two changes in 'require' for Lua 5.1:

1) Following Diego's suggestion, require "a.b" would first require "a".
Unlike his suggestion, however, fails in that require are not silently
ignored. (You can simply add an empty "init.lua" file into directory
"a" to satisfy that require.)

2) The Lua loader is called before the C loader. The motivation is that
Lua is more dynamic than C, and so it is easier to change/correct Lua
modules and they need precedence for those changes/corrections to have
effect.

-- Roberto