implemented finding of subtypes in section.find + new test
implementation of the find_section test and enabling it

Conflicts:
	test/__main__.py

Conflicts:
	test/__main__.py
Added License file
changed XMLWriter to write a version parameter of the Doc. XMLReader will read it back correctly
Merge pull request #29 from jgrewe/master

Added License file This closes issue #28 raised by @toddrjen
changed XMLWriter to write a version parameter of the Doc. XMLReader will read it back correctly
corrections for serialization of the document version
merged with old branch
removed unused comments
Merge pull request #30 from asobolev/master

solves issue #11
Merge pull request #27 from jgrewe/find_subtypes

Implementation of finding subtypes in section.find

ok
Merge branch 'master' of https://github.com/G-Node/python-odml