added: INSPIRE icon (pineapple) and clean up
fixed: statistics option for recurring fields
fixed: time before showing the tooltip
added: documentation about INSPIRE diffusion and usage constraints
updated: version date
added: share icon
added: first step to a QGIS plugin
wp: new way to choose diffusion rules
added: Polish
Merge pull request #20 from Guts/wipdev

Merging branches to make easier the development