Issue 485: Database get corrupted when column is renamed for which check constraint was defined inside create table statement.

Fix the combination of updating a table which contains an LOB, and reading from the LOB at the same time.
Previously it would throw an exception, now it works.

Use a weak dependency to the JTS jar file (allow to use H2 without the JTS jar file in the classpath)

Use a weak dependency to the JTS jar file (allow to use H2 without the JTS jar file in the classpath)