New command line LedgerTool. (RIPD-243)

* Retrieve and process summary or full ledgers.
* Search using arbitrary criteria (any Python function).
* Search using arbitrary formats (any Python function).
* Caches ledgers as .gz files to avoid repeated server requests.
* Handles ledger numbers, ranges, and special names like validated or closed.

bin/jsonpath_rw/__init__.py

@@ -0,0 +1,4 @@
+from .jsonpath import *
+from .parser import parse
+
+__version__ = '1.3.0'