[server] update headers

headers/header_spec.txt

src/libraries/utils/markdown.ml

src/libraries/utils/markdown.mli

src/plugins/server/Makefile.in

src/plugins/server/configure.ac

src/plugins/server/data.ml

src/plugins/server/data.mli

src/plugins/server/doc.ml

src/plugins/server/doc.mli

src/plugins/server/jbuffer.ml

src/plugins/server/jbuffer.mli

src/plugins/server/kernel_ast.ml

src/plugins/server/kernel_ast.mli

src/plugins/server/kernel_fc.ml

src/plugins/server/kernel_fc.mli

src/plugins/server/kernel_project.ml

src/plugins/server/kernel_project.mli

src/plugins/server/main.ml

src/plugins/server/main.mli

src/plugins/server/request.ml