chown now accepts names in addition to id for user and group

Closes #31
Merge Pull Request #72
Update changelog
Added tag 6.1 for changeset 55c924ecc419
Bumped to 6.2 in preparation for next release.
Rename path to Path. Fixes #68.

--HG--
extra : amend_source : bd95f9fa5abb51f66bed0a2fa959b0bae6e81418
Correct one test that fails under rename
Update tests to use preferred name.
Update changelog
Added tag 6.2 for changeset be72beb60a11
Bumped to 6.3 in preparation for next release.
Merge branch 'master' into hadoop
open is now based on io.open
use u() in the newline pattern
changed write_text to use newline patterns
removed unused line
changed write_lines to use newline patterns
fixed docs
Merge pull request #78 from simleo/enhanced_open

Enhanced open
Just pass arguments through to io.open