doxygen: add make targets to build man and latex

HTML will be build per default.

Makefile

 .all:
 
-.PHONY: all doc docclean welcome
+.PHONY: all doc doc-man doc-latex docclean welcome
 
 all: welcome
 	@echo ""
@@ -9,6 +9,12 @@ all: welcome
 doc:
 	"$(MAKE)" -BC doc/doxygen
 
+doc-man:
+	"$(MAKE)" -BC doc/doxygen man
+
+doc-latex:
+	"$(MAKE)" -BC doc/doxygen latex
+
 docclean:
 	"$(MAKE)" -BC doc/doxygen clean
 

doc/doxygen/Makefile

@@ -4,7 +4,15 @@ doc: html
 # by marking html as phony we force make to re-run Doxygen even if the directory exists.
 .PHONY: html
 html:
-	doxygen riot.doxyfile
+	( cat riot.doxyfile ; echo "GENERATE_HTML = yes" ) | doxygen -
+
+.PHONY: man
+man:
+	( cat riot.doxyfile ; echo "GENERATE_MAN = yes" ) | doxygen -
+
+.PHONY:
+latex:
+	( cat riot.doxyfile ; echo "GENERATE_LATEX= yes" ) | doxygen -
 
 clean:
 	-@rm -rf latex man html doxygen_objdb_*.tmp

doc/doxygen/riot.doxyfile

@@ -1039,7 +1039,7 @@ IGNORE_PREFIX          =
 # If the GENERATE_HTML tag is set to YES doxygen will generate HTML output
 # The default value is: YES.
 
-GENERATE_HTML          = YES
+GENERATE_HTML          = NO
 
 # The HTML_OUTPUT tag is used to specify where the HTML docs will be put. If a
 # relative path is entered the value of OUTPUT_DIRECTORY will be put in front of