Tonc cleanup and fixes

I've uploaded some newer tonc files today, mostly for devkitArm r21 compatibility. Because the linkscript for multiboot got b0rken somehow, I had to change all the demos to default to cart-builds. I intended to change to cart-boot later anyway, but not being able to build the demos properly with the latest devkit kinda forces me to do it now. I've also had to change the tier-3 makefiles because it used `-fno-expections' in the CXXFLAGS. This should of course have been `-fno-exceptions' (thanks muff).

There have also been a few changes in the text parts: build-specs are set to cart-boot there too now, and I fixed some broken links. I've also fixed a slew of spelling and grammar issues that Patater sent in. These part of the text shouldn't be gibberish anymore – just unintelligible :P.