Nuspell version 5.1.1

Added

• Add configuration option BUILD_TOOLS that can be used to disable building
  the CLI tool. It is ON by default. See #122.

Changed

• Made error reporting more detailed and robust. The message in the thrown
  exception is much richer when there are parsing errors. The library does
  not write directly to cerr, it does not pollute it. See #123.

Fixed

• Fix compiler warnings regarding usage of deprecated functions.
• Fix CLI tool on Windows + MSVC to properly accept arguments. Windows + MSVC
  now requires library getopt from Vcpkg. Fixes #122.