build: Add autotools option for those who want it

Closes #40.

autotools/Makefile.am

@@ -0,0 +1,7 @@
+bin_PROGRAMS	= lolcat censor
+lolcat_SOURCES	= ../lolcat.c
+censor_SOURCES	= ../censor.c
+
+LIBS		+= -lm
+CFLAGS		?= -O3
+AM_CFLAGS	 = -std=c11 -Wall -Wextra -Wno-sign-compare -Werror=implicit

autotools/README

@@ -0,0 +1,7 @@
+This directory contains an autotools config for building lolcat for those who need it. This is an alternative to the
+Makefile provided in the git root. Run it like so:
+
+cd autotools # go here
+./autogen.sh
+./configure
+make

autotools/autogen.sh

@@ -0,0 +1,36 @@
+#!/bin/bash
+
+auxdir=autoscripts
+
+set -x
+
+# aclocal generated files
+rm -rf aclocal.m4 autom4te.cache
+
+# autoheader generated files
+rm -f config.h.in
+
+# autoconf generated files
+rm -f configure
+
+# automake generated files
+rm -f ${auxdir}/{config.guess,config.sub,depcomp,install-sh,missing}
+rm -f Makefile.in
+
+# configure generated files
+rm -f config.h config.log config.status Makefile Makefile.in stamp-h1
+
+rm -f $(find ${auxdir} -type l 2>/dev/null)
+rmdir ${auxdir} 2>/dev/null
+
+if [[ "$1" == clean ]]; then
+	exit 0
+fi
+
+mkdir ${auxdir} 2>/dev/null
+
+aclocal
+autoheader
+autoconf
+automake --add-missing
+

autotools/configure.ac

@@ -0,0 +1,35 @@
+#                                               -*- Autoconf -*-
+# Process this file with autoconf to produce a configure script.
+
+AC_PREREQ([2.69])
+AC_INIT([lolcat], [1.2], [jaseg <github@jaseg.de>])
+AC_CONFIG_SRCDIR([../lolcat.c])
+AC_CONFIG_HEADERS([config.h])
+AC_CONFIG_AUX_DIR([autoscripts])
+AC_CANONICAL_TARGET
+AC_CANONICAL_HOST
+
+# Automake
+AM_INIT_AUTOMAKE([foreign subdir-objects])
+
+# Checks for programs.
+AC_PROG_CC
+AC_PROG_INSTALL
+
+# Checks for libraries.
+AC_CHECK_LIB([m], [cos])
+
+# Checks for header files.
+AC_CHECK_HEADERS([locale.h stdint.h stdlib.h string.h sys/time.h unistd.h wchar.h])
+
+# Checks for typedefs, structures, and compiler characteristics.
+AC_TYPE_SIZE_T
+AC_CHECK_HEADER_STDBOOL
+AC_TYPE_UINT8_T
+
+# Checks for library functions.
+AC_FUNC_STRTOD
+AC_CHECK_FUNCS([gettimeofday setlocale strchr strerror strstr wcwidth])
+
+AC_CONFIG_FILES([Makefile])
+AC_OUTPUT