Add WhatIf command line option to Build command

[ormico]

add an option to the ./dbpatch build that will just print (or output to file) all the actions (mostly the SQL that would have been executed) that would have been taken instead of changing the database.

This will still need to connect to the database to query the InstalledPatches (or whatever a particular plugin is using) in order to determine which plugins to execute and in what order.