Add wrapper shared library

[berchn]

This creates a wrapper shared library to hide the pass-by-value struct parameters from lisp. This was done to reduce the number of times C structs were being converted to lisp representations and vice versa. The result is that this has cut the conversion time by about half.

There is no longer a dependency on the CFFI fork due to these changes. If there is still an interest in getting this into quicklisp, it may be more feasible now.

[death]

Nice, I got this to work by re-adding ts-language as the return type argument to foreign-funcall. Otherwise a call to language-module would return no values (which is then interpreted as a nil and passed to ts-parser-set-language, resulting in a type error since a pointer is expected). Why was it removed?

Few more things that may be non-issues in practice but caught my eye are:

• bool (expands to _Bool) is used in the C file. Then type :boolean is used in the CFFI defcfun form. The latter type assumes :int representation by default, but the former is not guaranteed to be so. I would probably replace bool in the C file with int.
• Returned values from malloc calls are not checked for nullness.
• The wrapper file names are inconsistent: the C file uses underscores, while the shared object uses hyphens. I would use hyphens everywhere (Lisper after all).

[berchn]

Yeah, that's my bad on removing ts-language. I couldn't figure out what it was there for when I was reading the definition of foreign-funcall and evidently didn't dig far enough or look up the documentation online. I added it back in.

I switched bool over to int, but I'm of the opinion that it's a bug with CFFI if they were to ever not match on some system.

[death]

I see that Lisp code was added to check for null pointer result, which is fine, but the malloc results are not checked in the C code. I will merge this and add the checks. Thanks!