Move initialization to the Lua module itself

[kalrish]

Currently, luaotfload.sty loads the luaotfload-main Lua module and then (inmediatly) runs an initialization function (luaotfload.main()) offered by this module. This function is, in fact, never run again, and isn't intended to be run more than once, AFAICT.

Instead, do initialization directly in the Lua module, straight away.

Motivation behind this change:
One may want to dump a custom format (with LuaTeX). In order to make it feasible and useful, one has to dump all Lua modules in the format. To do this, one could hook into require's second searcher so as to save the loader function that it gets in a bytecode register. However, with the current state of affairs, this approach fails to save the initialization step done by calling luaotfload.main(). This can be solved by moving initialization to the Lua module itself.

[phi-gamma]

···<date: 2016-02-07, Sunday>···<from: Kalrish Bäakjen>···

Currently, luaotfload.sty loads the luaotfload-main Lua
module and then (inmediatly) runs an initialization function
(luaotfload.main()) offered by this module. This function is,
in fact, never run again, and isn't intended to be run more than
once, AFAICT.

The rationale is to separate module loading from execution. This
is by design.

One may want to dump a custom format (with LuaTeX). In order to
make it feasible and useful, one has to dump all Lua modules in
the format. To do this, one could hook into require's second
searcher so as to save the loader function that it gets in a
bytecode register. However, with the current state of affairs,
this approach fails to save the initialization step done by
calling luaotfload.main(). This can be solved by moving
initialization to the Lua module itself.

What’s wrong with wrapping Luaotfload in another Lua module and
then calling main() from there?

[phi-gamma]

Instead, do initialization directly in the Lua module, straight away.

BTW, we could make this a configuration option: Depending on
some variable, the main() would be executed directly after
loading the module. Open an issue if you’re still interested.