libticalcs (& libticables ?): make Nspire OS dumping work on all models

[debrouxl]

libticalcs only uses the dumb directory traversal hole which was available in OS 1.x, but that was fixed long ago. Implementing a dumper based on masquerading as another calculator, like BrandonW's Fron, should make libticalcs usable for dumping arbitrary OS - at least for now.