configure improved --with-xxx options

Rev: src/Makefile.src:1.11
Rev: src/README:1.2
Rev: src/configure.in:1.8
Rev: src/machine.h.in:1.7
Rev: src/modules/Makefile.src:1.7
Rev: src/modules/call_out/Makefile.src:1.4
Rev: src/modules/files/Makefile.src:1.4
Rev: src/modules/gdbmmod/Makefile.src:1.4
Rev: src/modules/gdbmmod/configure.in:1.2
Rev: src/modules/gmpmod/Makefile.src:1.4
Rev: src/modules/gmpmod/configure.in:1.3
Rev: src/modules/image/Makefile.src:1.4
Rev: src/modules/math/Makefile.src:1.4
Rev: src/modules/pipe/Makefile.src:1.4
Rev: src/modules/readlinemod/Makefile.src:1.4
Rev: src/modules/readlinemod/configure.in:1.4
Rev: src/modules/regexp/Makefile.src:1.4
Rev: src/modules/spider/Makefile.src:1.4
Rev: src/modules/sprintf/Makefile.src:1.4
Rev: src/testsuite.in:1.4