Fix more issues with range table and improve its documentation

# Conflicts:
#	h2/src/main/org/h2/engine/ConnectionInfo.java

Fix RangeTable.getRowCount() for non-default step

ValueBoolean constants are not cleared and may be used directly

code cleanups via IntelliJ IDEA inspections

Add remaining "time unit" management in "date_trunc"

Check parameters in JdbcPreparedStatement.addBatch()

Update changelog.html