* 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
* rename get_size to axes_rank and move axes buffer to axes.hpp
* added fill experiments
* faster and simpler fill_impl
* faster specializations for linearize_value
- Tests and benchmarks now only include the headers they really need.
- Warnings turned off for tests that compile with external boost libs that are not warning free
* InputIterator concept requires that the decrement of a postfix-incremented iterator is valid, now it is
* added detached_accessor to that end
* update benchmark plot, better docs
* fetching google benchmark with cmake
* use new thread-safe accumulator in histogram_parallel_filling
* update boost, root and gsl benchmarks to use google benchmark
* fixes broken msvc build
* smaller xml files for testing serialization
* fixing many warnings on msvc
* bug-fixes to mp_int regarding operators and new tests to check their behavior
* don't expect iterable histogram::at to have size method
* build benchmarks in release mode
* test everything by default when b2 is run on project directory
* more test coverage
* 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
