Add Makefile option to use the DMALLOC (debug malloc) library.

I didn't have much success in finding bugs using it, but it works
out-of-the-box on my setup, so it may be useful in the future.

git-svn-id: https://svn.eduke32.com/eduke32@2254 1a8010ca-5511-0410-912e-c29ae57300e0

polymer/eduke32/Makefile.common

@@ -44,6 +44,7 @@ RELEASE?=1
 DEBUGANYWAY?=0
 KRANDDEBUG?=0
 EFENCE?=0
+DMALLOC?=0
 OPTLEVEL?=2
 PROFILER?=0
 MUDFLAP?=0
@@ -145,6 +146,10 @@ ifneq (0,$(EFENCE))
     LIBS+= -lefence
     BASECFLAGS+= -DEFENCE
 endif
+ifneq (0,$(DMALLOC))
+    LIBS+= -ldmalloc
+    BASECFLAGS+= -DDMALLOC
+endif
 
 BASECXXFLAGS= -fno-exceptions -fno-rtti
 BASEASFLAGS=-s #-g

polymer/eduke32/build/include/compat.h

@@ -93,6 +93,8 @@
 
 #ifdef EFENCE
 # include <efence.h>
+#elif defined DMALLOC
+# include <dmalloc.h>
 #endif
 
 #if defined(_MSC_VER)