[eacsl:doc] Update user manual with latest E-ACSL outputs and URL

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

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

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

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

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

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

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

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

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