#53 add user to group uses json, added test, better api (failures via
exception, not result value)
#63 fixed: Tracker doesn't implement Identifiable and Serializable
minor refactoring: moved "join" operation from RedmineManager to a separate class (Joiner).
It is likely there's a replacement for it in Google Guava libs.
#64 Fixed time-entry comment serialization
#54 fixed: JSONBuilder does not write all the values of a custom field when the field is a list.
set version to 1.16 for the release
set version to 1.17-SNAPSHOT
#70

Added support for journal details
* Added support for enumerations
switched tests to run with the last Redmine 2.2.0
set version to 1.17 for the release.
fixed basic authentication (used badly formatted headers)
set version to 1.18 for the release.
add Issue Watchers
* "Watchers" tests ignored untill we have Redmine 2.3
refactoring: renamed the recently added method related to watchers.
fixed Missing Field
Merge pull request #83 from jeeeyul/master

I fixed missing field(description) in Writing JSON of Attachment.
fixed Parsing error Time Entry Activity
Merge branch 'master' of https://github.com/jeeeyul/redmine-java-api