re-organise LobStorageBackend code a little, so we don't need to correct the precision of a CLOB later on

git-svn-id: http://h2database.googlecode.com/svn/trunk@5104 e6896862-9d19-0410-bfb3-e9fa5d50e656
fix previous commit

git-svn-id: http://h2database.googlecode.com/svn/trunk@5105 e6896862-9d19-0410-bfb3-e9fa5d50e656
inline the "create temporary LOBs" methods into the constructor so that I can make more fields final

git-svn-id: http://h2database.googlecode.com/svn/trunk@5106 e6896862-9d19-0410-bfb3-e9fa5d50e656
improve method and field naming  "useCompression" -> "isCompressed"

git-svn-id: http://h2database.googlecode.com/svn/trunk@5107 e6896862-9d19-0410-bfb3-e9fa5d50e656