* include/libmes.h (dtoab): Declare.
* lib/mes/ntoab.c (ntoab): Update.
* lib/mes/dtoab.c: New file.
* build-aux/configure-lib.sh (libmes_SOURCES, libc_tcc_SOURCES): Add
it.
* lib/tests/mes/90-dtoab.c: Test it.
* lib/tests/stdio/90-sprintf.c: Test it.
* build-aux/check-mescc.sh (tests): Run it, against...
* lib/tests/mes/90-dtoab.stdout: ...baseline.
* lib/stdio/vfprintf.c (vfprintf): Support %f, even more naive support
for %e, %E, %g, %G.
* lib/stdio/vsnprintf.c (vsnprintf): Likewise.
* include/libmes.h (abtod): Declare.
* lib/mes/abtod.c: New file.
* build-aux/configure-lib.sh (libmes_SOURCES, libc_tcc_SOURCES): Add
it.
* lib/mes/abtol.c: Update.
* lib/stdlib/strtod.c: Use it to implement; move from stub/strtod.
* lib/tests/mes/90-abtod.c: Test it.
* lib/tests/mes/90-abtod.stdout: Baseline.
* build-aux/check-mescc.sh (tests): Run it.
* lib/posix/execl.c (vexec): New function.
(execl): Use it.
* lib/posix/execlp.c: New file.
* build-aux/configure-lib.sh (libc_tcc_SOURCES): Add it.
* lib/libc+gnu.c: Include it.
* include/unistd.h (execlp): Declare.
* lib/tests/posix/90-execlp.c: New file.
* lib/tests/posix/90-execlp.stdout: New file.
* build-aux/check-mescc.sh: Test it.
* build-aux/connfigure-lib.sh: Split from build-lib.sh
* build-aux/build-lib.sh: Include it.
* build-aux/bootstrap.sh.in: New file.
* configure.sh: Substitute it.