flyway#754 fix bug on quote together with comment

This bug is common for all databases. It occurs when quote follows the comment start or precedes the comment end without whitespaces.
I add sql statement for testing all databases into common V1__Comment.sql script.
A also add V1__Comment.sql to dbsupport/oracle/comment for testing single line comment. It cannot be put into common file because mysql syntax is not supported single line comments without whitspace after --

My pull requet #764 is wrong. This is correct.