annotate libtests/0007/short-description @ 401:a8a5f2ca5380 api-inversion

Invert audioDB::l2norm / audiodb_l2norm()

We now have some functions that shouldn't be exported to the user of the
library, but are used in more than one source file; case in point:
audiodb_sync_header().  Make a new audioDB-internals.h file for them,
and while we're at it put the scary mmap()-related macros in there too.

We can't delete audioDB::unitNormAndInsertL2() quite yet, because it's
used in insertion too, but we can delete the non-append branches.
That's not very much code to lose, but every little helps.

short query [no -l] error with lib