allow pymarc.Record subclasses to be written by MARCWriter

* `type` demands equality of types, while `isinstance` caters for inheritance
Added JSONReader and a test case for it
remove print() invocation and future import for better(?) backward compatibility
Merge pull request #37 from adjam/master

Add JSONReader
upped version for release
doc fix
variation on the fix proposed in #41. fixes #41
Merge branch 'master' of github.com:edsu/pymarc
not sure how we lost the test suite in setup.py ...
upped version for release
Added support of shorthand membership testing for records and fields
Merge pull request #43 from DavidChouinard/master

Added support of shorthand membership testing for records and fields
Merge pull request #36 from miku/feature/subclass

allow pymarc.Record subclasses to be written by MARCWriter
upped version for release
Fix inconsistent use of tabs and spaces in indentation
Merge pull request #44 from termim/master

Fix inconsistent use of tabs and spaces in indentation
not needed to run test suite
warn when 2 indicators are not found, but try to use what we find, and move on. fixes #45
point to the ticket in case we are wondering some time in the future
upped version