Fix for Issue #7, generalizing multi-line schemas tests:

- Made Repository implement Closeable and changed all Repository implementations accordingly.
- Moved the LocalFileSystem's tests to a new AbstractTestPersistentRepository class, which LocalFS and ZK tests extend.
- Actually found a bug in the previous implementation of the multi-line test and LocalFS repo, and fixed those bugs.
- Enabled (and added config for) the Jetty capability to hook into the shutdown event, to make sure repos are always closed.
Added .gitignore for IntelliJ IDEA *.iml files
Issue #11: log via slf4j; Issue #12: deal with NIO locks on Windows
Remove exec bit from xml files
Converted additional System.err.println to Logger.error
Fixed exec bit
Removed duplicate property and executable bit
Adding Ernest to the contributor's list
Merge pull request #19 from FelixGV/add_ernest_to_contributors

Adding Ernest to the contributor's list
Merged from upstream
Merge branch 'master' of github.com:schema-repo/schema-repo
Fixed line endings in a few files (accidentally introduced CRLF)
Significant refactoring of Repository class hierachy