#47 exclude logic

[Alex Roytman]

I believe it is very important to support "exclude" logic in
middlegen

1. exclude tables by pattern
2. exclude columns by pattern (on table level and task
level) One of the reason is that quite often tables have
columns which should not be exposed to object model
i.e. optimistic lock columns, timestaps, class for
heterogenious O/R mappings etc
3. exclude table/column in prefs file by mentioning this
table/column fwith flag exclude="true"

[Aslak Hellesřy]

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user_id=49846

this is not a bug, but a fr.