Single threaded init of prelude.

prelude and prelude_ objects.
Finished inspecting globals.

Added TODOs.
Removed re-assignment of done and undefined.

undefined was changed to have external linkage, making the call to
alloc_Undefined redundant. The effect of the call to alloc_done was
moved inside gracelib_argv in gracelib.c .
Added locks around globals.

Added locks for iomodule, sysmodule, Float64_Interned,
String_Interned_1, Strings_allocated and the debug call.