[GraphView] rewrite theme support

[vantu5z]

Attempt to provide opportunity to add custom themes 12108 (aditional fields).
Fix 11397 (underline call name).
Family theme is only one and hard coded for now.

Added experimental feature to display attributes (for now - eye and hair colors).

To add custom person theme you should put it to GraphView/themes folder.
You should have some python knowledge and know Gramps structure to create custom themes.

Example for occupation :

# -*- coding: utf-8 -*-

from default_0 import Theme as DefaultTheme
from gramps.gen.lib import EventType

from gramps.gen.const import GRAMPS_LOCALE as glocale
try:
    _trans = glocale.get_addon_translator(__file__)
except ValueError:
    _trans = glocale.translation
_ = _trans.gettext

class Theme(DefaultTheme):
    """
    Use person DefaultTheme as base.
    Add occupation info.
    """
    THEME_KIND = 'person'

    def __init__(self, dot_generator, options, functions):
        DefaultTheme.__init__(self, dot_generator, options, functions)
        self.index = 5
        self.name = _('Example occupation')

        self.html = ('%(img)s'
                     '%(name)s'
                     '%(dates)s'
                     '%(occup)s'    # we want add occupation data befor tags
                     '%(tags)s')

    def get_some_data(self, person):
        """
        Function to get some data from database.
        For example it is occupation.
        """
        occupation = ''
        event_ref_list = person.get_event_ref_list()
        for event_ref in event_ref_list:
            event = self.functions.dbstate.db.get_event_from_handle(
                event_ref.ref)
            if event.type == EventType.OCCUPATION:
                if occupation:
                    occupation += '<BR/>' + event.get_description()
                else:
                    occupation = event.get_description()

        return self.table_row_fmt % occupation if occupation else ''

    def build(self, person, html):
        """
        Build html table.
        Get if from DefaultTheme and edit.
        """       
        return html % {'img': self.get_image_str(person),
                       'name': self.get_name_str(person),
                       'dates': self.get_dates_str(person),
                       'tags': self.get_tags_str(person),
                       'attrs' : self.get_attrs_str(person),
                       'occup' : self.get_some_data(person)     # add this line
                      }