Fix Makefile.am's txcreatesign and blanktx dependencies.

This commit needs to be reverted after AAA is deployed.

This will hopefully fix the Travis CI failures on the dev branch.

Quoting @domob1812: "Some time ago Bitcoin introduced tests for `bitcoin-tx` that change the version number of the created transactions.  Since a change here is incompatible to Namecoin (because Namecoin uses a fixed `nVersion` to distinguish Namecoin transactions; something I proposed to remove with a fork some time ago in the forum), I've "reverted" these changes.  Thus this file [txcreatesignv1.hex] does not exist for Namecoin, it is instead `test/data/txcreatesign.hex`."

refs bitcoin#142

Makefile.am

@@ -226,10 +226,8 @@ EXTRA_DIST += \
     test/util/bctest.py \
     test/util/bitcoin-util-test.py \
     test/util/data/bitcoin-util-test.json \
-    test/util/data/blanktxv1.hex \
-    test/util/data/blanktxv1.json \
-    test/util/data/blanktxv2.hex \
-    test/util/data/blanktxv2.json \
+    test/util/data/blanktx.hex \
+    test/util/data/blanktx.json \
     test/util/data/tt-delin1-out.hex \
     test/util/data/tt-delin1-out.json \
     test/util/data/tt-delout1-out.hex \
@@ -271,9 +269,8 @@ EXTRA_DIST += \
     test/util/data/txcreatescript3.json \
     test/util/data/txcreatescript4.hex \
     test/util/data/txcreatescript4.json \
-    test/util/data/txcreatesignv1.hex \
-    test/util/data/txcreatesignv1.json \
-    test/util/data/txcreatesignv2.hex
+    test/util/data/txcreatesign.hex \
+    test/util/data/txcreatesign.json
 
 CLEANFILES = $(OSX_DMG) $(BITCOIN_WIN_INSTALLER)