Various fixes around makefiles

* $PREFIX is uppercase (I have no idea why I put it lowercase before).
* "install" rules is OS specific and moved to new OS specific files. So that they can be included last.
* "examples" rule defines the list of examples to execute.
* Travis launches the "test" rule.

.travis.yml

@@ -7,10 +7,5 @@ script:
   - sudo apt-get update
   - sudo apt-get install libgtk-3-dev -y || sudo apt-cache search libgtk3
   - make -f GNUmakefile
-  - make -f GNUmakefile example EXAMPLE=histogram
-
-# Only working things are added here... Some interesting commands would be:
-#  - make -f GNUmakefile examples
-#  - make -f GNUmakefile test
-#
-# But they both won't work
+  - make -f GNUmakefile examples
+  - make -f GNUmakefile test 

GNUmakefile

@@ -8,11 +8,6 @@ MAKEFLAGS += --no-print-directory
 OUTDIR = out
 OBJDIR = .obj
 
-# default install prefix is /usr
-ifndef prefix
-	prefix=/usr
-endif
-
 # MAME does this so :/
 ifeq ($(OS),Windows_NT)
 	OS = windows
@@ -64,12 +59,10 @@ example: libui
 
 # TODO examples rule? --> That's it right ?
 examples:
-	for d in $$(ls examples); do $(MAKE) -f GNUmakefile example EXAMPLE=$$d ; done
+	@$(MAKE) -f GNUmakefile example EXAMPLE=histogram
+	#@$(MAKE) -f GNUmakefile example EXAMPLE=controlgallery 
 
 .PHONY: examples
 
-install: libui
-	cp out/libui.so $(DESTDIR)$(prefix)/lib/libui.so.0
-	ln -s libui.so.0 $(DESTDIR)$(prefix)/lib/libui.so
-	cp ui.h ui_unix.h $(DESTDIR)$(prefix)/include/ui.h
-
+install:
+	@$(MAKE) -f build/GNUmakefile.libui install inlibuibuild=1

build/GNUmakefile.libui

@@ -39,3 +39,6 @@ else
 endif
 
 include build/GNUbase$(TOOLCHAIN).mk
+
+# install rule is OS specific
+include $(OS)/GNUinstall.mk

darwin/GNUinstall.mk

@@ -0,0 +1,9 @@
+ifndef PREFIX
+    PREFIX=/usr
+endif
+
+# Incorrect for Mac Os X, this should be easy to fix
+install: $(OUT)
+	cp $(OUT) $(DESTDIR)$(PREFIX)/lib/libui.0.dylib
+	ln -s libui.so.0 $(DESTDIR)$(PREFIX)/lib/libui.so
+	cp ui.h ui_$(OS).h $(DESTDIR)$(PREFIX)/include/

unix/GNUinstall.mk

@@ -0,0 +1,8 @@
+ifndef PREFIX
+    PREFIX=/usr
+endif
+
+install: $(OUT)
+	cp $(OUT) $(DESTDIR)$(PREFIX)/lib/libui.so.0
+	ln -fs libui.so.0 $(DESTDIR)$(PREFIX)/lib/libui.so
+	cp ui.h ui_$(OS).h $(DESTDIR)$(PREFIX)/include/

windows/GNUinstall.mk

@@ -0,0 +1,3 @@
+install:
+	@echo "No install for windows !"
+	@exit 1