autotools: remove

Since 2008, autotools has served us well - thank you!

However, mu is now using meson build, and it's time to remove the
autotools support -- one build system is enough.

mu4e/Makefile.am

@@ -1,68 +0,0 @@
-## Copyright (C) 2008-2017 Dirk-Jan C. Binnema <djcb@djcbsoftware.nl>
-##
-## This program is free software; you can redistribute it and/or modify
-## it under the terms of the GNU General Public License as published by
-## the Free Software Foundation; either version 3 of the License, or
-## (at your option) any later version.
-##
-## This program is distributed in the hope that it will be useful,
-## but WITHOUT ANY WARRANTY; without even the implied warranty of
-## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-## GNU General Public License for more details.
-##
-## You should have received a copy of the GNU General Public License
-## along with this program; if not, write to the Free Software Foundation,
-## Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
-
-include $(top_srcdir)/gtest.mk
-
-SUBDIRS=
-
-info_TEXINFOS=mu4e.texi
-mu4e_TEXINFOS=fdl.texi
-
-dist_lisp_LISP=			\
-	mu4e-actions.el		\
-	mu4e-bookmarks.el	\
-	mu4e-compose.el		\
-	mu4e-contacts.el	\
-	mu4e-context.el		\
-	mu4e-contrib.el		\
-	mu4e-draft.el		\
-	mu4e-folders.el		\
-	mu4e-headers.el		\
-	mu4e-icalendar.el	\
-	mu4e-lists.el		\
-	mu4e-helpers.el		\
-	mu4e-main.el		\
-	mu4e-mark.el		\
-	mu4e-message.el		\
-	mu4e-config.el		\
-	mu4e-org.el		\
-	mu4e-search.el		\
-	mu4e-server.el		\
-	mu4e-speedbar.el	\
-	mu4e-update.el		\
-	mu4e-vars.el		\
-	mu4e-view.el		\
-	mu4e.el			\
-	obsolete/org-mu4e.el
-
-
-EXTRA_DIST=			\
-	mu4e-about.org
-
-CLEANFILES=			\
-	*.elc
-
-doc_DATA =			\
-	mu4e-about.org
-
-##
-## Change as needed.
-##
-BUILDPATH=mu4e
-TEXINFO_CSS_PATH=~/Sources/ext/texinfo-css
-fancyhtml:
-	mkdir -p $(BUILDPATH) ; cp -R $(TEXINFO_CSS_PATH)/static $(BUILDPATH)
-	makeinfo --html --css-ref=static/css/texinfo-klare.css -o $(BUILDPATH) mu4e.texi