build: build manpage by default if rst2man is detected

Add building the manpage to the all target (which is also the default
target). This fixes the behavior that "make install" tried to build the
manpage if it wasn't built yet.

Add rst2man detection to configure, and disable rst2man usage in the all
and install targets if it hasn't been found. You can still build or
install the man page manually (by using the install-mpv-man target),
but the all and install targets won't attempt to use rst2man.

Additionally, building/installing the manpage by default can be
explicitly inhibited using the --disable-manpage configure option.
It's possible to avoid rst2man by using "make mpv install-no-man" as
well.

Makefile

@@ -282,13 +282,15 @@ OBJECTS         += $(OBJECTS-yes)
 
 DEP_FILES = $(patsubst %.S,%.d,$(patsubst %.cpp,%.d,$(patsubst %.c,%.d,$(SOURCES:.m=.d) $(SOURCES:.m=.d))))
 
-ALL_PRG         += mpv$(EXESUF)
-
-INSTALL_TARGETS += check_rst2man       \
-                   install-mpv     \
-                   install-mpv-man
+ALL_TARGETS     += mpv$(EXESUF)
 
 INSTALL_NO_MAN_TARGETS += install-mpv
+INSTALL_TARGETS = $(INSTALL_NO_MAN_TARGETS)
+
+ifeq ($(BUILD_MAN),yes)
+    INSTALL_TARGETS += install-mpv-man
+    ALL_TARGETS     += DOCS/man/en/mpv.1
+endif
 
 DIRS =  . \
         audio \
@@ -321,7 +323,7 @@ endif
 
 ###### generic rules #######
 
-all: $(ALL_PRG)
+all: $(ALL_TARGETS)
 
 %.1: %.rst
 	$(RST2MAN) $< $@
@@ -407,9 +409,6 @@ DOCS/man/en/mpv.1: DOCS/man/en/af.rst \
 
 ###### installation / clean / generic rules #######
 
-check_rst2man:
-	@which $(RST2MAN) > /dev/null 2>&1 || (printf "\n\trst2man not found. You need the docutils (>= 0.7) to generate the manpages. Alternatively you can use 'install-no-man' rule.\n\n" && exit 1)
-
 install: $(INSTALL_TARGETS)
 
 install-no-man: $(INSTALL_NO_MAN_TARGETS)

configure

@@ -382,6 +382,7 @@ Miscellaneous options:
   --target=PLATFORM      target platform (i386-linux, arm-linux, etc)
   --enable-static        build a statically linked binary
   --with-install=PATH    path to a custom install program
+  --disable-manpage      do not build and install manpage [auto]
 
 Advanced options:
   --enable-shm              enable shm [autodetect]
@@ -499,6 +500,7 @@ def_stream_cache="#define CONFIG_STREAM_CACHE 1"
 def_priority="#undef CONFIG_PRIORITY"
 def_pthread_cache="#undef PTHREAD_CACHE"
 need_shmem=yes
+_build_man=auto
 for ac_option do
   case "$ac_option" in
   --help|-help|-h)
@@ -732,6 +734,9 @@ for ac_option do
   --enable-sortsub) _sortsub=yes ;;
   --disable-sortsub) _sortsub=no ;;
 
+  --enable-manpage) _build_man=yes ;;
+  --disable-manpage) _build_man=no ;;
+
   *)
     echo "Unknown parameter: $ac_option" >&2
     exit 1
@@ -917,6 +922,16 @@ if [ -f "$(which rst2man.py)" ] ; then
   _rst2man=rst2man.py
 fi
 
+echocheck "whether to build manpages with rst2man"
+if test "$_build_man" = auto ; then
+    _build_man=no
+    command_check "$_rst2man" --version && _build_man=yes
+else
+    _build_man=no
+fi
+echores "$_build_man"
+
+
 TMPC="$mplayer_tmpdir/tmp.c"
 TMPCPP="$mplayer_tmpdir/tmp.cpp"
 TMPEXE="$mplayer_tmpdir/tmp$_exesuf"
@@ -3228,6 +3243,7 @@ EXTRALIBS          = $extra_ldflags $_ld_static $_ld_lm $extra_libs $libs_mplaye
 GETCH = $_getch
 TIMER = $_timer
 RST2MAN = $_rst2man
+BUILD_MAN = $_build_man
 
 EXESUF      = $_exesuf
 EXESUFS_ALL = .exe