[Dev-luatex] no more running to the pool

I also removed the need for luatex.pool. That is to say: it is still created by tangle, but now it is only used at compile-time. A perl script generates a C file containing a large static array of strings, the file is compiled-in, and the code therein is in turn used to initialize the internal string pool. This is a hack of course (the static array never goes away), but the removal of the separate pool file is worth the extra memory usage (about 44k data). At least, I believe so. Sometime in the future, I will probably write code that uses the C array directly. Cheers, Taco