This allows users to configure the Mail Transfert Agent (MTA) of their
choice.
* configure.ac: Add '--with-sendmail' option.
(SENDMAIL): Default to 'sendmail -t'.
* NEWS: Announce it.
* src/mcron/redirect.scm (with-mail-out): Assume the MTA is reading the
message for recipients.
* build-aux/guix.scm: Remove 'which' from the native-inputs.
Fetching third-party files inside a make rule is convenient and less
error prone since 'make' has access to '$srcdir'.
* build-aux/gnu-fetch: Delete.
* maint.mk (WGET, git_sv_host, sv_git_am, sv_git_gl)
(fetchfiles): New macros.
(fetch): New target.
* HACKING <Updating auxilary scripts>: Update instructions.
* tests/init.sh: New test framework from Gnulib.
* tests/basic.sh: New test.
* Makefile.am (TESTS): Add it.
(TEST_EXTENSIONS): Add '.sh'.
(SH_LOG_COMPILER): Use 'pre-inst-env'.
(EXTRA_DIST): Add 'tests/init.sh'.
* build-aux/pre-inst-env.in: export $srcdir for shell tests.
* build-aux/git-version-gen: New script.
* configure.ac (AC_INIT): Use it.
(AC_REQUIRE_AUX_FILE): Distribute it.
* Makefile.am (.version): New target.
(BUILT_SOURCES, EXTRA_DIST): Add it.
(dist-hook): Generate ".tarball-version".
* .gitignore: Update.
This allows using 'mcron' before it is installed without hardcoding the
local build environment in the executable.
* build-aux/pre-inst-env.in: New script.
* configure.ac (AC_CONFIG_FILES): Create it.
(AC_CONFIG_HEADER): Add 'config.h'.
(moduledir): New variable.
(PACKAGE_LOAD_PATH): new C preprocessor macro.
* mcron.c: Include "config.h".
(main): Don't overwrite Guile load paths.
(inner_main): Prepend Mcron modules load paths.
* Makefile.am (.scm.go, doc/mcron.1): Use 'pre-inst-env'.
(mcron_CFLAGS): Remove GUILE_LOAD_PATH macro.
(noinst_SCRIPTS): New variable.
* .gitignore: Update.
