* fixed #1261, overflow when calculating work

* tests for difficulty_to_boundary

* return !U256::zer() for boundary <= 1

clarify build instructions

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[ci skip]

fixed #1255

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* Restrict network key file permissions

* Check for overflow in str to bigint conversion

* RLP decoder overflow check

windows installer + parity start ui cli option

ipc lib version bump

[ci skip]

Syncing improvements

removed redundant if condition

README: rustup and windows instructions

* Networking refactoring

* Fixed typo

* Trace logging

* Updated dependencies for windows build

* Windows fixes

* use mio 0.5

* nix build

* Windows build fix

* style

* removed unused import

* ipc crate version bump

* ipc config for named pipes

* tweaks and fixes

* tweaks and fixes

* final version bump

* Fixed tests

* Disable color output on windows

* Added missing doc