Readme updates.
Merge branch 'master' of github.com:mapbox/rasterio
Merge branch 'master' of https://github.com/brendan-ward/rasterio
Merge branch 'master' of github.com:mapbox/rasterio
Add --meta and --tags options.

These pretty print a dataset's meta dict and tags and exit.
Switch to '' as const value.
Add verbosity control to rio_insp.

Also give GDAL its own logger.
Remove script from tool.py
First cut at datasets doc.
More about reading datasets.
Add image.
More about dataset attributes.
Use Cython's property for crs and transform.

Closes #73.
Add a GDAL error context.

Using a with statement like:

    with g_errs():
        ds = _gdal.GDALOpen('foo.tif')

On exit, the last GDAL error is converted to a Python exception.

Closes #75.
_err.pxd file not needed.
Remove unnecessary code, add docstrings.

See #75.
We only need one of these ctx managers ever.
Convert creation option values to strings.

Closes #76.
An example of parallel processing.

See #60.
Merge branch 'master' of github.com:mapbox/rasterio