Update libsnark to our fork.

depends/packages/libsnark.mk

@@ -1,18 +1,12 @@
 package=libsnark
 $(package)_version=0.1
-$(package)_download_path=https://github.com/scipr-lab/$(package)/archive/
+$(package)_download_path=https://github.com/zcash/$(package)/archive/
 $(package)_file_name=$(package)-$($(package)_git_commit).tar.gz
 $(package)_download_file=$($(package)_git_commit).tar.gz
-$(package)_sha256_hash=b5ec84a836d0d305407d5f39c8176bae2bb448abe802a8d11ba0f88f17e6d358
-$(package)_git_commit=69f312f149cc4bd8def8e2fed26a7941ff41251d
+$(package)_sha256_hash=43b0c921e8a1d556e70cf5c63c921db54f151842eb3cada029e3b92095e7b6f9
+$(package)_git_commit=a7031481fd8d2360337321401fe8e24f0359317a
 
-$(package)_dependencies=libgmp
-$(package)_patches=1_fix_Wl_flag.patch 2_include_iota_header.patch
-
-define $(package)_preprocess_cmds
-    patch -p1 < $($(package)_patch_dir)/1_fix_Wl_flag.patch && \
-    patch -p1 < $($(package)_patch_dir)/2_include_iota_header.patch
-endef
+$(package)_dependencies=libgmp libsodium
 
 define $(package)_build_cmds
   CXXFLAGS="-fPIC -DBINARY_OUTPUT -DNO_PT_COMPRESSION=1" $(MAKE) lib DEPINST=$(host_prefix) CURVE=ALT_BN128 MULTICORE=1 NO_PROCPS=1 NO_GTEST=1 NO_DOCS=1 STATIC=1 NO_SUPERCOP=1 FEATUREFLAGS=-DMONTGOMERY_OUTPUT

depends/patches/libsnark/1_fix_Wl_flag.patch

@@ -1,19 +0,0 @@
-commit 728c1ace30f2338b86331f0b83559409198e1f74
-Author: Taylor Hornby <havoc@defuse.ca>
-Date:   Wed Sep 9 16:46:48 2015 -0600
-
-    g++-4.9 requires commas to include the argument to ``rpath`` as a linker flag.
-
-diff --git a/Makefile b/Makefile
-index 5f59388..68e91bb 100644
---- a/Makefile
-+++ b/Makefile
-@@ -18,7 +18,7 @@ DEPSRC = depsrc
- DEPINST = depinst
- 
- CXXFLAGS += -I$(DEPINST)/include -Isrc
--LDFLAGS += -L$(DEPINST)/lib -Wl,-rpath $(DEPINST)/lib
-+LDFLAGS += -L$(DEPINST)/lib -Wl,-rpath,$(DEPINST)/lib
- LDLIBS += -lgmpxx -lgmp -lboost_program_options
- # OpenSSL and its dependencies (needed explicitly for static builds):
- LDLIBS += -lcrypto -ldl -lz

depends/patches/libsnark/2_include_iota_header.patch

@@ -1,31 +0,0 @@
-commit c437365ec98ec77754287594d2d3748901d0d176
-Author: Taylor Hornby <taylor@defuse.ca>
-Date:   Wed May 18 10:49:58 2016 -0600
-
-    Include header required for std::iota.
-
-diff --git a/src/common/data_structures/integer_permutation.cpp b/src/common/data_structures/integer_permutation.cpp
-index f9f9327..378ea7e 100644
---- a/src/common/data_structures/integer_permutation.cpp
-+++ b/src/common/data_structures/integer_permutation.cpp
-@@ -15,6 +15,7 @@
- 
- #include <algorithm>
- #include <cassert>
-+#include <numeric>
- #include <unordered_set>
- 
- namespace libsnark {
-diff --git a/src/common/data_structures/sparse_vector.tcc b/src/common/data_structures/sparse_vector.tcc
-index 26429a5..cfc5d75 100644
---- a/src/common/data_structures/sparse_vector.tcc
-+++ b/src/common/data_structures/sparse_vector.tcc
-@@ -16,6 +16,8 @@
- 
- #include "algebra/scalar_multiplication/multiexp.hpp"
- 
-+#include <numeric>
-+
- namespace libsnark {
- 
- template<typename T>