[Qgis-developer] Raster providers

[Alexander Bruy]

Hi Radim

I found some issues with new raster providers (tested on r15453).

1. Applying a style to layer triggers statistic calculation. If I apply
one style and then another statistics calculates twice.

2. In Metadata tab (Layer properties dialog) there is no raster
statistics even when it calculated.

3. On Histogram tab progress bar is inactive during statistics calculation.
This is a bit confusing especially when raster has many bands

Thanks
-- 
Alexander Bruy