* introduce offset for faster linearization of non-growing axes
* added traits::is_inclusive and constexpr bool inclusive() methods for builtin axes
* bug fixes for fill method when weight array is used with non-inclusive axis and when growing axes are used
* bug fix of axis::options::test(...)
* coverage tested with gcc-8, updated CONTRIBUTING.md with coverage info
* provide unsafe access to buffer
* factored mp_int out into separate header and renamed to large_int
* refined adding behavior
* more warnings and comeback of coverage variant
* better coverage reporting
* Travis uses b2 and codecov now
* replacing boost::multiprecision with custom implementation to avoid the dependency
* improved axis implementation: `update` is now a normal method
* introduced use_default tag type to set defaults
* whitespace fixes and doc update
Add missing copyright header to CMakeLists.txt.
Rename build directory to tools.
Update Travis CI and AppVeyor scripts.
Ignore variants of build directory.
Ignore CMakeSettings.json used with CMake integration for VS2017.
Ignore Visual Studio and Visual Studio Code local settings folder.