message: update makefile to build emp only when it changes
diff: @@ -32,9 +32,9 @@ LINKER_OPTIONS = $(INCLUDE_ARCHIVES_START) install/lib/libOTExtensionBristol.a i
  LIBRARIES_DIR = -L$(HOME)/boost_1_60_0/stage/lib -Linstall/lib
  LD_FLAGS =
  -all:: libs libscapi
  -libs:: compile-emp compile-ntl compile-blake compile-miracl compile-otextension compile-otextension-malicious compile-otextension-bristol
  -libscapi:: directories $(SLib)
  +all: libs libscapi
  +libs: compile-emp-tool compile-emp-ot compile-emp-m2pc compile-ntl compile-blake compile-miracl compile-otextension compile-otextension-malicious compile-otextension-bristol
  +libscapi: directories $(SLib)
  directories: $(OUT_DIR)
  $(OUT_DIR):
  @@ -63,34 +63,34 @@ obj/mid_layer/%.o: src/mid_layer/%.cpp
  tests:: all
  $(Program)
  -compile-emp:prepare-emp compile-emp-tool compile-emp-ot compile-emp-m2pc
  -
  prepare-emp:
  @mkdir -p $(builddir)/EMP
  @cp -r lib/EMP/. $(builddir)/EMP
  @cmake -DALIGN=16 -DARCH=X64 -DARITH=curve2251-sse -DCHECK=off -DFB_POLYN=251 -DFB_METHD="INTEG;INTEG;QUICK;QUICK;QUICK;QUICK;LOWER;SLIDE;QUICK" -DFB_PRECO=on -DFB_SQRTF=off -DEB_METHD="PROJC;LODAH;COMBD;INTER" -DEC_METHD="CHAR2" -DCOMP="-O3 -funroll-loops -fomit-frame-pointer -march=native -msse4.2 -mpclmul" -DTIMER=CYCLE -DWITH="MD;DV;BN;FB;EB;EC" -DWORD=64 $(builddir)/EMP/relic/CMakeLists.txt
  @cd $(builddir)/EMP/relic && $(MAKE)
  @cd $(builddir)/EMP/relic && $(MAKE) install
  + @touch prepare-emp
  compile-emp-tool:prepare-emp
  @cd $(builddir)/EMP/emp-tool
  @cmake $(builddir)/EMP/emp-tool/CMakeLists.txt
  @cd $(builddir)/EMP/emp-tool/ && $(MAKE)
  @cd $(builddir)/EMP/emp-tool/ && $(MAKE) install
  - @touch compile-emp-tool
  + # @touch compile-emp-tool
  compile-emp-ot:prepare-emp
  @cd $(builddir)/EMP/emp-ot
  @cmake $(builddir)/EMP/emp-ot/CMakeLists.txt
  @cd $(builddir)/EMP/emp-ot/ && $(MAKE)
  @cd $(builddir)/EMP/emp-ot/ && $(MAKE) install
  - @touch compile-emp-ot
  + # @touch compile-emp-ot
  compile-emp-m2pc:prepare-emp
  @cd $(builddir)/EMP/emp-m2pc
  @cmake $(builddir)/EMP/emp-m2pc/CMakeLists.txt
  @cd $(builddir)/EMP/emp-m2pc/ && $(MAKE)
  @touch compile-emp-m2pc
  + @touch compile-emp
  compile-blake:
  @echo "Compiling the BLAKE2 library"
  