Change occurrences of "optiq" and "eigenbase" in java code to "calcite".
Rename packages.

org.apache.calcite becomes org.apache.calcite.schema;
org.apache.calcite.impl.interpreter becomes org.apache.calcite.interpreter;
other org.apache.calcite.impl sub-packages move to org.apache.calcite.adapter;
org.apache.calcite.impl classes move to org.apache.calcite.schema.impl.
Fix up.