libc/uClibc: do not systematically use pre-generated locale data

It seems that using pre-generated locale data can be more problematic
than usefull in some circumstances.

Offer a config knob to enable/disable use of the pregen locale data.
Also, do not extract pregen locales data ourselves, it's broken.

syntax: glob

# Generated files

Makefile

ct-ng

docs/ct-ng.1

docs/ct-ng.1.gz

paths.mk

scripts/crosstool-NG.sh

scripts/saveSample.sh

scripts/showTuple.sh

# Temporaries

.*.swp

log.*

# Working files

kconfig/conf

kconfig/mconf

kconfig/**.o

kconfig/**.dep

config.gen/

.config

.config.old

targets/