noux: enable 64bit builds for foc and nova

Fixes #816
base: allocate contexts solely inside context area

Reserve first bit in bit allocator for main thread of context allocator and
remove special cases in context allocator. Without the reservation there is
is one context outside the context area allocated.

Fixes #1100
ldso: flush the log console in 'errx()'

The error message given to the 'errx()' function does not always contain a
'\n' character. Adding 'printf("\n")' ensures that the message appears on
the log console.

Fixes #1103.