Restructure error and success messages for the editor.

closes #1368
- merged the Maps for Error/Notification Messages into one JSON-structure
- this structure is more translation-friendly and influenced by I18n-standards.

Merged the Error and Message Map into one structure

The new JSON-structure is more translation friendly and similiar to i18n.
Removing error handling using process.stderr

- process.stdin/out/error is problematic, see https://github.com/joyent/node/issues/3584
Merge pull request #1579 from ErisDS/master-fix

Removing error handling using process.stderr
Restore support for using ghost as a npm module fixes #1326
Merge pull request #1569 from hswolff/ghost-module-support
Merge pull request #1410 from schmanu/iss1368

Added new notification message on updating a post.