add libpseudotalloc as super-simplistic talloc replacement

In tightly embedded builds (--enable-embedded), we want the ability to
replace talloc with a very simple heap allocator to avoid the complexity
of talloc without modifying all our code that assumes talloc.

This will break the hierarchical notion of the allocator, but
libosmo{core,gsm,coding,codec} don't rely on that anyway.

Change-Id: Ie341034076f242a813f081919dd09d845775ad35
diff --git a/src/Makefile.am b/src/Makefile.am
index c083936..5724055 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -6,6 +6,10 @@
 AM_CPPFLAGS = -I$(top_srcdir)/include -I$(top_builddir)/include
 AM_CFLAGS = -Wall $(TALLOC_CFLAGS)
 
+if ENABLE_PSEUDOTALLOC
+AM_CPPFLAGS += -I$(top_srcdir)/src/pseudotalloc
+endif
+
 lib_LTLIBRARIES = libosmocore.la
 
 libosmocore_la_LIBADD = $(BACKTRACE_LIB) $(TALLOC_LIBS)