2 new features for session export view

Allow output to be pretty-formatted, ask for confirmation
before overwriting existing file
Fixed test for session:export:view, added CHANGELOG
Merge pull request #36 from phpcr/session_export_improvements

2 new features for session export view
Added ability to import a file into the repository
Updated command
Updated changelog
Merge pull request #34 from phpcr/import_file

Added ability to import a file into the repository
iAdded --level option to list