refactor:

- merge xmldsig and xmlenc into a single package
- implement thread-safe error capture
- implement encryption using libxmlsec, discarding the go implementation

setup_test.go

@@ -0,0 +1,10 @@
+package xmlsec
+
+import (
+	"testing"
+
+	. "gopkg.in/check.v1"
+)
+
+// Hook up gocheck into the "go test" runner.
+func Test(t *testing.T) { TestingT(t) }