Conform to QGIS 2.0 plugin structure: add metadata, modified doCartogram.py because of changes in the Qt API
Fix report bug in https://github.com/cfarmer/cartogram-plugin/pull/2#issuecomment-39080283, conform to PEP8 style rules
Merge pull request #2 from CristianCantoro/master

Conform to QGIS 2.0 plugin structure