[userman] update and document new options

src/plugins/e-acsl/doc/Changelog

src/plugins/e-acsl/doc/userman/biblio.bib

src/plugins/e-acsl/doc/userman/changes.tex

src/plugins/e-acsl/doc/userman/examples/instrumented_first.c

src/plugins/e-acsl/doc/userman/examples/printf.c

src/plugins/e-acsl/doc/userman/examples/strcpy.c

src/plugins/e-acsl/doc/userman/introduction.tex

src/plugins/e-acsl/doc/userman/macros.tex

src/plugins/e-acsl/doc/userman/provides.tex