variable naming - improve and make consistent

git-svn-id: http://h2database.googlecode.com/svn/trunk@4785 e6896862-9d19-0410-bfb3-e9fa5d50e656
add a comment

git-svn-id: http://h2database.googlecode.com/svn/trunk@4786 e6896862-9d19-0410-bfb3-e9fa5d50e656
capitalise comment, makes it easier to read.

git-svn-id: http://h2database.googlecode.com/svn/trunk@4787 e6896862-9d19-0410-bfb3-e9fa5d50e656
capitalise comment, makes it easier to read.

git-svn-id: http://h2database.googlecode.com/svn/trunk@4788 e6896862-9d19-0410-bfb3-e9fa5d50e656
rename PageStore#systemSession to PageStore#pageStoreSession, to distinguish it from Database#systemSession

git-svn-id: http://h2database.googlecode.com/svn/trunk@4789 e6896862-9d19-0410-bfb3-e9fa5d50e656