BACKWARDS-INCOMPATIBLE-CHANGE: Making the table-name-override easier to grok, and retaining compatibility with FeinCMS table names by default.

For legacy projects:

If FEINCMSTOOLS_INCLUDE_CONTENT_TYPE_BASE_NAMES = False, do nothing, except erase the setting.

Else if FEINCMSTOOLS_INCLUDE_CONTENT_TYPE_BASE_NAMES = True then:

rename FEINCMSTOOLS_INCLUDE_CONTENT_TYPE_BASE_NAMES to FEINCMSTOOLS_USE_LEGACY_TABLE_NAMES

OR, to migrate your content types to use 'proper' table names, make migrations like this:

```
content_types = ['mediafile', 'oembed', 'oneofffile', 'oneoffimage', 'rawhtml', 'textile']

class Migration(SchemaMigration):

    def forwards(self, orm):
        for c in content_types:
            db.rename_table('page_page_page%scontent' % c, 'page_page_%scontent' % c)


    def backwards(self, orm):
        for c in content_types:
            db.rename_table('page_page_%scontent' % c, 'page_page_page%scontent' % c)
```
Merge branch 'master' of git://github.com/ixc/glamkit-feincmstools