[Tracker] Complete service type description

[Ivan Frade <ivan frade nokia com>]

Hi all,

 In order to remove all hardcoded stuff in tracker-metadata we should
modify a little bit the default.services file:

1) Setting the properties "HasMetadata", "HasFulltext" and "HasThumbs"
in the service type descriptions. (And set the default value in the
database to False).

 Right now, those properties are not set in the file. They have the
default value in the database schema, and that value ("True") is not
correct!. It is working because Tracker use hardcoded information to
decide if the service type has fulltext/metadata/thumbs


2) Adding a new property ("FilterContents" or "UseMimeFilter"?) when the
service type has fulltext. So we can know when to use a filter to
extract the contents.

 It is hardcoded that "Text" and "Development" categories dont use
filters.

 Is there any problem with these changes?

 Thanks,

Ivan