Unroll loops in light_compute

* Update CHANGELOG for 1.6.9 stable release.

* [WIP] Prepare CHANGELOG for 1.7.0 beta release.

* Contract warp

* Update changes for 1.7.0

* Update description for 1.7.0 in changelog

* Update Changelog for 1.7.0 beta and 1.6.10 stable

* Address reviews for the Changelog.

* Fix blog URL in changelog.

* Fix typo in Changelog.

* Update changelog for 1.7.0 beta and 1.6.10 stable

* Update wallet library binaries

* Update the links

Add custom panic hook

The panic hook prints a backtrace, the panic message, file, and line
number, and a plea to report bugs.

Place RETURNDATA behind block number gate

I also tried unrolling the 256-iteration loop further below, but it actually caused a
slowdown (my guess is either branch prediction stopped kicking in or the instruction
cache was being maculated).

asynchronous rob authored Jul 18, 2017 and Arkadiy Paronyan committed Jul 18, 2017

* bump last tick just before printing info and restore sync detection

* bump kovan snapshot version

* Fixed sync tests

* Fixed rpc tests

Giuseppe Bertone authored Jul 18, 2017 and Arkadiy Paronyan committed Jul 18, 2017

Solved the "TraceDB resync required" issue when trying to use "--tracing on" option just after a DB kill operation;

fix for builds.snapcraft.io