Generate man pages from asciidoc

Working directly with g/roff is a pain.
Also changed the formatting of toxic.conf.5 a bit.

Signed-off-by: Loui Chang <louipc.ist@gmail.com>

build/Makefile

@@ -4,12 +4,15 @@ VERSION = $(TOXIC_VERSION)_r$(REV)
 
 BASE_DIR = $(shell cd .. && pwd -P)
 CFG_DIR = $(BASE_DIR)/cfg
+DOC_DIR = $(BASE_DIR)/doc
 SRC_DIR = $(BASE_DIR)/src
 PREFIX = /usr/local
 BINDIR = $(PREFIX)/bin
 DATADIR = $(PREFIX)/share/toxic
 MANDIR = $(PREFIX)/share/man
 
+MANFILES = toxic.1 toxic.conf.5
+
 LIBS = libtoxcore ncursesw libconfig
 
 CFLAGS = -std=gnu99 -pthread -Wall -g
@@ -53,7 +56,7 @@ endif
 -include $(CFG_DIR)/checks/check_features.mk
 
 # Targets
-all: toxic
+all: toxic doc
 
 toxic: $(OBJ)
 	@echo "  LD    $@"
@@ -64,8 +67,18 @@ toxic: $(OBJ)
 	@$(CC) $(CFLAGS) -o $*.o -c $(SRC_DIR)/$*.c
 	@$(CC) -MM $(CFLAGS) $(SRC_DIR)/$*.c > $*.d
 
+doc: $(MANFILES)
+
+%: $(DOC_DIR)/%.asc
+	@echo "  Generating man page $@"
+	@a2x -f manpage -a revdate=$(shell git log -1 --date=short --format="%ad" $<) \
+	-a manmanual="toxic manual" -a mansource=toxic \
+	-a manversion=$(VERSION) -a datadir=$(DATADIR) $<
+	@mv $(DOC_DIR)/$@ .
+
 clean:
 	rm -rf *.d *.o toxic
+	rm -rf $(MANFILES)
 
 -include $(OBJ:.o=.d)