Fix javadoc errors on JDK 1.8

Fix javadoc errors causing javadoc compilation to fail under JDK 1.8.
JDK 1.8 appears to be more strict about javadoc formatting and was
throwing a number of errors and warnings that didn't appear previously.
Merge remote-tracking branch 'osm/master'

Conflicts:
	osmosis-
areafilter/src/main/java/org/openstreetmap/osmosis/areafilter/common/PolygonFileReader.java
	osmosis-
core/src/main/java/org/openstreetmap/osmosis/core/database/FeaturePopulator.java
	osmosis-
core/src/main/java/org/openstreetmap/osmosis/core/domain/v0_6/Bound.java
	osmosis-
core/src/main/java/org/openstreetmap/osmosis/core/domain/v0_6/Node.java
	osmosis-
core/src/main/java/org/openstreetmap/osmosis/core/domain/v0_6/Relation.java
	osmosis-
core/src/main/java/org/openstreetmap/osmosis/core/domain/v0_6/RelationMember.java
	osmosis-
core/src/main/java/org/openstreetmap/osmosis/core/domain/v0_6/Tag.java
	osmosis-
core/src/main/java/org/openstreetmap/osmosis/core/domain/v0_6/Way.java
	osmosis-
core/src/main/java/org/openstreetmap/osmosis/core/domain/v0_6/WayNode.java
	osmosis-
core/src/main/java/org/openstreetmap/osmosis/core/util/TileCalculator.java
	osmosis-
tagtransform/src/main/java/org/openstreetmap/osmosis/tagtransform/impl/TransformHelper.java
	osmosis-
xml/src/main/java/org/openstreetmap/osmosis/xml/v0_6/XmlWriter.java
	osmosis-
xml/src/main/java/org/openstreetmap/osmosis/xml/v0_6/impl/BoundWriter.java
	osmosis-
xml/src/main/java/org/openstreetmap/osmosis/xml/v0_6/impl/OsmWriter.java