Previously we would fail in some parts of the code if we did not have a
premade configuration, now we use any code that was marked as Linux, BSD and
Solaris as our basis in order to support building unknown Unix systems.
Some files were trying to access the global includes directy in the
build area with things like #include <api/c/tt_c.h>, which is now
wrong. Se we fix all of those up. tt_c.h and tttk.h are now global,
so we no longer need to root around various build dirs to find them.
TT builds again.
