Generalize test support.
Keep tests in "tests" subdir of each module.
Use global test runner, use "make check" for running tests.
Convert "sample" module to new unittest scheme.
Convert "ffi" module to new unittest scheme.
ffi: More tests.
README: Add links and references.
Add squirrel-lang:squirrel3-pfalcon repo as a submodule.
Update paths to squirrel-lang.
Add sources and Makefile to build interpreter with import support.
Add .gitignore.
Add quick start instructions.
Elaborate ffi module interface, make FFI func prepare be method of lib object.

Now there's lib.func(rettype, name, [argtype]), i.e. explicit ffi.sym() call is
not needed.
Implement support for variables. var = lib.var(type, name); var.get()
ffi: Cleanup.
ffi: Update tests for latest API.
Add test for accessing variables (errno).
Rename API sqrat_import() to sq_import().
sqimport: Keep reference to module name object while we use it.
Pulled error printing changes from squirrel-lang.