Check the Content-Type header that is returned from the RPC server. Only
if it is `application/json` the data is supposed to be parsed as JSON.
This gives better reporting if the HTTP server happens to return an error that is
not JSON-formatted, which is the case if it happens at a lower level
before JSON-RPC kicks in.
Before: `Unexpected exception caught during testing: No JSON object could be decoded`
After: `JSONRPC error: non-JSON HTTP response with '403 Forbidden' from server`
Avoid an infinite loop in encoding, by ensuring EncodeDecimal
returns a string. round(Decimal) used to convert it to
float, but it no longer does in python 3.x. Strings are
supported since #6380, so just use that.
Python's httplib does not graciously handle disconnections from the http server, resulting in BadStatusLine errors.
See https://bugs.python.org/issue3566 "httplib persistent connections violate MUST in RFC2616 sec 8.1.4."
This was fixed in Python 3.5.
Work around it for now.
Taught bitcoind to close the HTTP connection after it gets a 'stop' command,
to make it easier for the regression tests to cleanly stop.
Move bitcoinrpc files to correct location.
Tidied up the python-based regression tests.
Wladimir J. van der Laan