More Makefile.unix tweaks

Drop some unneeded CINCLUDES.
Drop the VPATH stuff altogether.  It's entirely unused here, and some of
the paths in it don't even exist and apparently never have in this tree.
Drop the 'default' rule, without it there, 'all' already is the default.
Drop $(TARGET) from all, it already includes 'lib' which is $(TARGET).
Declare phony targets PHONY.

Makefile.unix

@@ -50,25 +50,15 @@ ldlibs-from-libs                = $(addprefix -l,$(1))
 
 WARNINGS = -Wall -W -Wstrict-prototypes -Wextra -Wcast-align -Wnested-externs -Wshadow
 CFLAGS  += -O2 -g $(WARNINGS) -DOPUS_BUILD
+CINCLUDES = include silk celt
+
 ifdef FIXED_POINT
 CFLAGS += -DFIXED_POINT=1 -DDISABLE_FLOAT_API
+CINCLUDES += silk/fixed
+else
+CINCLUDES += silk/float
 endif
 
-CINCLUDES += include/ \
-	silk/ \
-	silk/float/ \
-	silk/fixed/ \
-	celt/ \
-	src/
-
-# VPATH e.g. VPATH = src:../headers
-VPATH = ./ \
-	silk/interface \
-	silk/src_FIX \
-	silk/src_FLP \
-	silk/src_SigProc_FIX \
-	silk/src_SigProc_FLP \
-	test
 
 LIBS = m
 
@@ -109,9 +99,7 @@ OPUSCOMPARE_SRCS_C = src/opus_compare.c
 OPUSCOMPARE_OBJS := $(patsubst %.c,%$(OBJSUFFIX),$(OPUSCOMPARE_SRCS_C))
 
 # Rules
-default: all
-
-all: $(TARGET) lib opus_demo opus_compare
+all: lib opus_demo opus_compare
 
 lib: $(TARGET)
 
@@ -134,3 +122,5 @@ force:
 
 clean:
 	rm -f opus_demo$(EXESUFFIX) opus_compare$(EXESUFFIX) $(TARGET) $(OBJS) $(OPUSDEMO_OBJS)
+
+.PHONY: all lib clean