[e-acsl] merging the e-acsl-mmodel branch into the main branch

src/plugins/e-acsl/Makefile.in

src/plugins/e-acsl/TODO

src/plugins/e-acsl/env.ml

src/plugins/e-acsl/env.mli

src/plugins/e-acsl/gcc_test.sh

src/plugins/e-acsl/main.ml

src/plugins/e-acsl/misc.ml

src/plugins/e-acsl/misc.mli

src/plugins/e-acsl/mpz.ml

src/plugins/e-acsl/mpz.mli

src/plugins/e-acsl/options.ml

src/plugins/e-acsl/options.mli

src/plugins/e-acsl/pre_analysis.ml

src/plugins/e-acsl/pre_analysis.mli

src/plugins/e-acsl/quantif.ml

src/plugins/e-acsl/share/e-acsl/e_acsl.h

src/plugins/e-acsl/share/e-acsl/e_acsl_gmp.h

src/plugins/e-acsl/share/e-acsl/e_acsl_gmp_types.h

...plugins/e-acsl/share/e-acsl/memory_model/e_acsl_bittree.c

...plugins/e-acsl/share/e-acsl/memory_model/e_acsl_bittree.h