Merge #207: Fix python 27 incompatibility by defining FileNotFoundError

173e860 add version magic to python2 compat fix in rpc.py (Florian)
98ecbc6 work around a python 27 incompatibility by defining FileNotFoundError (Florian)

Pull request description:

  This small pul requests fixes a compatibility with python27 by by defining FileNotFoundError.

Tree-SHA512: c0e32a1be986f1bb4c4ebfa3b06d0e50f2e442f2b06f16b66e681838b39b69e562d5cee6019b2cfd606b42260efb1cf0ba6fe0b9d8f531f60e46dc512ce1b49d

Author: petertodd

bitcoin/rpc.py

@@ -42,6 +42,13 @@
 except ImportError:
     import urlparse
 
+# needed for python2 compatibility
+if sys.version < '3':
+    try:
+        FileNotFoundError
+    except NameError:
+        FileNotFoundError = IOError
+
 import bitcoin
 from bitcoin.core import COIN, x, lx, b2lx, CBlock, CBlockHeader, CTransaction, COutPoint, CTxOut
 from bitcoin.core.script import CScript