Improve contributor guidelines
Manual merge of pr/286 from Mike Benowit
Merge branch 'contributing' of https://github.com/aaime/geotools into aaime-contributing
replace hack page and separate out role from procedure
Clarify small / large contributions and test cases, remove invitation to contact module maintainers directly.
Merge pull request #311 from jodygarnett/contributing

Improve Contributor guidelines
Another GEOT-3407 related fix
[GEOT-4609] Unclosed iterator in VectorToRasterProcess
[GEOT-4606] different offsets for same dash-stroke
sort out contributor role with clear advantages, responsibilities and procedure
Fix CSV tutorial to use "the_geom" and explain shape file limitations
Feedback from andrea and fix up the tutorial text to match
Merge pull request #313 from jodygarnett/geot_4595

Fix CSV tutorial to use "the_geom" and explain shape file limitations (GEOT-3595)
feedback from andrea on advantages of being a module maintainer
Merge pull request #312 from jodygarnett/contributor

sort out contributor role with clear advantages, responsibilities
GEOT-2333: removeSchema
Merge pull request #308 from geosolutions-it/GEOT-2333

GEOT-2333: removeSchema
Adding doc and updating images for datastore section
Updating missing imports for doc samples
Merge branch 'master' of https://github.com/geotools/geotools into pamsupport