Incompatible TIGCCLIB change (default.h inclusion removal)

[kkofler]

Commit 4b9c4b5 breaks backwards compatibility!
Minimal test case:

#define USE_TI89
#include <float.h>

void _main(void)
{
}

This compiles with the real TIGCC, but will produce a "No target calculators specified" error after the above commit.

One of the basic principles of TIGCCLIB is that all headers include <default.h>, so that users can rely on the fact that including any TIGCCLIB header is enough to apply options, without having to check on a case-to-case basis whether that actually holds for any particular header. So Lionel's commit is totally user-unfriendly, in addition to being incompatible. But even just the incompatibility would render it unacceptable.