Initial commit.

This is the initial GeoGig codebase contribution to LocationTech.
As required by LocationTech contribution process, it's a single
commit, resulting from squashing the whole project history.
This initial commit is based on commit 8e5f210b08982d74fc807d592b64f9bee031b975
from the original project repository at https://github.com/boundlessgeo/GeoGig.
adding screenmap filtering support
Add support for ScreenMap filtering to the GeoGigDataStore
Use changeType() instead of changeType to avoid a false negative
remove superfluous logging statement
allow commits to also be cached
Lazy Feature building and use Node bounds for building the point attribute if possible
better logging for screenmap usage
notice.html and initial about.html

Signed-off-by: Jody Garnett <jody.garnett@gmail.com>
Ignore huge envelope requests from the renderer when possible
Allow the DataStore factory to be given a resolver for the repo location
Replace all occurrencies of @opengeo.org by @boundlessgeo.com
Don't flood the logs on failed DataStore.canProcess()
scripts used to update headers
record of header information from github history search
update headers with header generated from git history
Update/Restore files requiring origional header
Remove odbl data example from javadoc
Add support for osm import to use multiple rules.

If a mappings file contained more than one rule that
apply to a given feature, only the first of them was being
applied.
This patch makes sure that mapping with multiple rules to
multiple trees is possible on import, and that both
osm export-shp and osm export-sl can also export to multiple
tables given a mappings file with multiple rules.
Let CommandHooks know what the exception thrown is when a command failed