update the changelog, so much has happened
mktestfile creates test metadata too
update the test metadata to contain the correct shape
flush the file pointer when creating a test array
document setting the metadata
give the testfiles better names, that correspond to the examples in the README
print the repr if the magic isn't found

E.G:
blpk: error: the magic marker 'blpk' is missing from the bloscpack header,
instead we found: '\x89PNG'
update the meta and info examples
fix the woring when explaining append
fix a typo
note about the convention in the command line examples
update the TODO, still loads to do
correct the version of python-blosc that we want to use in future
fix cram output
make some metadata in the cram
cram test metadata
fix cram to have correct metadata
cram tests for basic appending
add the introduction of cram to the changelog