New package ASDF.jl

I have created a package ASDF.jl that implements the ASDF (Advanced Scientific Data Format) file format This file format has similarities with HDF5, but is mostly human-readable, simpler, and does not require an external C library. ASDF.jl is based on the “asdf” Python package

As usual, comments and feedback are welcome. Not all advanced features are wrapped yet, but the basic functionality is there: Read/write arbitrary metadata, and handle multi-dimensional arrays efficiently.

I assume (but have no benchmarks to back this up) that the ASDF format might be more efficient than HDF5 for storing small data or arbitrary Julia objects. It thus might in the future make a good back-end for JLD.jl