Add "bitcoin-tx" command line utility and supporting modules.

This is a simple utility that provides command line manipulation of
a hex-encoded TX. The utility takes a hex string on the command line
as input, performs zero or more mutations, and outputs a hex string
to standard output.

This utility is also an intentional exercise of the "bitcoin library"
concept. It is designed to require minimal libraries, and works
entirely without need for any RPC or P2P communication.

See "bitcoin-tx --help" for command and options summary.

src/Makefile.am

@@ -34,6 +34,7 @@ LIBBITCOIN_COMMON=libbitcoin_common.a
 LIBBITCOIN_CLI=libbitcoin_cli.a
 LIBBITCOIN_UTIL=libbitcoin_util.a
 LIBBITCOIN_CRYPTO=crypto/libbitcoin_crypto.a
+LIBBITCOIN_UNIVALUE=univalue/libbitcoin_univalue.a
 LIBBITCOINQT=qt/libbitcoinqt.a
 
 noinst_LIBRARIES = \
@@ -41,6 +42,7 @@ noinst_LIBRARIES = \
   libbitcoin_common.a \
   libbitcoin_cli.a \
   libbitcoin_util.a \
+  univalue/libbitcoin_univalue.a \
   crypto/libbitcoin_crypto.a
 if ENABLE_WALLET
 BITCOIN_INCLUDES += $(BDB_CPPFLAGS)
@@ -58,6 +60,8 @@ if BUILD_BITCOIN_CLI
   bin_PROGRAMS += bitcoin-cli
 endif
 
+bin_PROGRAMS += bitcoin-tx
+
 .PHONY: FORCE
 # bitcoin core #
 BITCOIN_CORE_H = \
@@ -178,6 +182,13 @@ crypto_libbitcoin_crypto_a_SOURCES = \
   crypto/sha1.h \
   crypto/ripemd160.h
 
+# univalue JSON library
+univalue_libbitcoin_univalue_a_SOURCES = \
+  univalue/univalue.cpp \
+  univalue/univalue_read.cpp \
+  univalue/univalue_write.cpp \
+  univalue/univalue.h
+
 # common: shared between bitcoind, and bitcoin-qt and non-server tools
 libbitcoin_common_a_CPPFLAGS = $(BITCOIN_INCLUDES)
 libbitcoin_common_a_SOURCES = \
@@ -229,6 +240,7 @@ nodist_libbitcoin_util_a_SOURCES = $(srcdir)/obj/build.h
 bitcoind_LDADD = \
   $(LIBBITCOIN_SERVER) \
   $(LIBBITCOIN_COMMON) \
+  $(LIBBITCOIN_UNIVALUE) \
   $(LIBBITCOIN_UTIL) \
   $(LIBBITCOIN_CRYPTO) \
   $(LIBLEVELDB) \
@@ -267,6 +279,17 @@ endif
 bitcoin_cli_CPPFLAGS = $(BITCOIN_INCLUDES)
 #
 
+# bitcoin-tx binary #
+bitcoin_tx_LDADD = \
+  $(LIBBITCOIN_UNIVALUE) \
+  $(LIBBITCOIN_COMMON) \
+  $(LIBBITCOIN_UTIL) \
+  $(LIBBITCOIN_CRYPTO) \
+  $(BOOST_LIBS)
+bitcoin_tx_SOURCES = bitcoin-tx.cpp
+bitcoin_tx_CPPFLAGS = $(BITCOIN_INCLUDES)
+#
+
 if TARGET_WINDOWS
 bitcoin_cli_SOURCES += bitcoin-cli-res.rc
 endif