In rpc-tests.py, don't override BITCOIND and BITCOINCLI if they're
already set. Makes it possible to run the tests with either another tree
or the GUI.
This replaces using inv messages to announce new blocks, when a peer requests
(via the new "sendheaders" message) that blocks be announced with headers
instead of inv's.
Since headers-first was introduced, peers send getheaders messages in response
to an inv, which requires generating a block locator that is large compared to
the size of the header being requested, and requires an extra round-trip before
a reorg can be relayed. Save time by tracking headers that a peer is likely to
know about, and send a headers chain that would connect to a peer's known
headers, unless the chain would be too big, in which case we revert to sending
an inv instead.
Based off of @sipa's commit to announce all blocks in a reorg via inv,
which has been squashed into this commit.
Rebased-by: Pieter Wuille
bip65-cltv.py is based on the earlier BIP66 soft-fork RPC test
implemented by Pieter Wuille's 819bcf9b99
bip65-cltv-p2p.py is based on the earlier BIP66 P2P test by Suhas
Daftuar's d76412b068
1) created rpc-tests.py
2) deleted rpc-tests.sh
3) travis.yml points to rpc-tests.py
4) Modified Makefile.am
5) Updated README.md
6) Added tests_config.py and deleted tests-config.sh
7) Modified configure.ac with script to set correct path in tests_config.py