makefile: add targets to build the level-editor alone

makefile

@@ -124,19 +124,25 @@ windows-release64: build/projects/vs2017 build/windows64/bin/luajit.exe
 rebuild-glib-resources:
 	$(MAKE) -j$(MAKE_JOBS) -R -C tools/level_editor/resources rebuild
 
-tools-linux-debug64: linux-debug64
+level-editor-linux-debug64:
 	$(MAKE) -j$(MAKE_JOBS) -R -C build/projects/linux level-editor config=debug
-tools-linux-release64: linux-development64
+level-editor-linux-release64:
 	$(MAKE) -j$(MAKE_JOBS) -R -C build/projects/linux level-editor config=release
 
+tools-linux-debug64: linux-debug64 level-editor-linux-debug64
+tools-linux-release64: linux-development64 level-editor-linux-release64
+
 tools-windows-debug64: windows-debug64
 tools-windows-release64: windows-development64
 
-tools-mingw-debug64: build/projects/mingw
+level-editor-mingw-debug64: build/projects/mingw
 	$(MAKE) -j$(MAKE_JOBS) -R -C build/projects/mingw level-editor config=debug
-tools-mingw-release64: build/projects/mingw
+level-editor-mingw-release64: build/projects/mingw
 	$(MAKE) -j$(MAKE_JOBS) -R -C build/projects/mingw level-editor config=release
 
+tools-mingw-debug64: level-editor-mingw-debug64
+tools-mingw-release64: level-editor-mingw-release64
+
 .PHONY: docs
 docs:
 	$(MAKE) -C docs/ html