Only create the state dir if asked for a restartable build:
- introduce the config dir, where components can store their config files
- move the munged uClibc config file to the config dir
- now, the state dir really is an indication that a build can be restarted

Thanks to Groleo Marius <groleo@gmail.com> for spotting the inconsistency
of the state dir usage, and suggesting this change.

/trunk/scripts/build/libc/uClibc.sh | 6 3 3 0 +++---
/trunk/scripts/crosstool-NG.sh.in | 9 7 2 0 +++++++--
/trunk/scripts/functions | 15 12 3 0 ++++++++++++---
3 files changed, 22 insertions(+), 8 deletions(-)

 source config/global.in

 source config/target.in

 source config/toolchain.in

 source config/kernel.in

 source config/gmp_mpfr.in

 source config/binutils.in

 source config/cc.in

 source config/libc.in

 source config/tools.in

 source config/debug.in