Based on Fedora patch, rebased for 1.5.5.

--- src/Makefile.old	2016-07-12 22:58:56.364814328 -0500
+++ src/Makefile	2016-07-12 22:59:02.521605818 -0500
@@ -40,7 +40,7 @@ CC_TEMP:=$(CC)
 override CXX=$(TOOLSET_PREFIX)$(CXX_TEMP)
 override CC=$(TOOLSET_PREFIX)$(CC_TEMP)
 
-INCLUDES= -I. -Ishared -Iengine -Igame -Ienet/include -Isupport
+INCLUDES= -I. -Ishared -Iengine -Igame -Isupport
 
 STRIP=
 ifeq (,$(findstring -g,$(CXXFLAGS)))
@@ -83,7 +83,7 @@ BIN_SUFFIX=_native
 endif
 endif
 CLIENT_INCLUDES= $(INCLUDES) -I/usr/X11R6/include `sdl2-config --cflags`
-CLIENT_LIBS= -Lenet -lenet -L/usr/X11R6/lib -lX11 `sdl2-config --libs` -lSDL2_image -lSDL2_mixer -lz -lGL
+CLIENT_LIBS= -lenet -L/usr/X11R6/lib -lX11 `sdl2-config --libs` -lSDL2_image -lSDL2_mixer -lz -lGL
 endif
 ifneq (,$(findstring linux,$(PLATFORM)))
 CLIENT_LIBS+= -lrt
@@ -161,7 +161,7 @@ SERVER_INCLUDES= -DSTANDALONE $(INCLUDES
 SERVER_LIBS= -mwindows $(STD_LIBS) -L$(WINDLL) -L$(WINLIB) -lzlib1 -lenet -lws2_32 -lwinmm
 else
 SERVER_INCLUDES= -DSTANDALONE $(INCLUDES)
-SERVER_LIBS= -Lenet -lenet -lz
+SERVER_LIBS= -lenet -lz
 endif
 SERVER_OBJS= \
 	shared/crypto-standalone.o \
@@ -223,10 +223,10 @@ $(APPSERVER)_windows$(BIN_SUFFIX): $(SER
 	$(WINDRES) -i $(APPNAME).rc -J rc -o $(APPNAME).res -O coff
 	$(CXX) $(CXXFLAGS) -o $@ $(APPNAME).res $(SERVER_OBJS) $(SERVER_LIBS)
 
-$(APPCLIENT)$(BIN_SUFFIX): $(LIBENET) $(CLIENT_OBJS)
+$(APPCLIENT)$(BIN_SUFFIX): $(CLIENT_OBJS)
 	$(CXX) $(CXXFLAGS) $(LDFLAGS) -o $@ $(CLIENT_OBJS) $(CLIENT_LIBS)
 
-$(APPSERVER)$(BIN_SUFFIX): $(LIBENET) $(SERVER_OBJS)
+$(APPSERVER)$(BIN_SUFFIX): $(SERVER_OBJS)
 	$(CXX) $(CXXFLAGS) $(LDFLAGS) -o $@ $(SERVER_OBJS) $(SERVER_LIBS)
 
 client: $(APPCLIENT)$(APPMODIFIER)$(BIN_SUFFIX)