Move search from kiwi

* Move kiwi.ui.search into stoqlib:
  * SearchContainer -> s.g.s.searchcontainer
  * SearchSlaveDelegate -> s.g.s.searchslave
  * search filters -> s.g.s.searchfilters
  * search options -> s.g.s.searchoptions
  * search columns -> s.g.columns
* Move stoqlib.gui.base.search into s.g.s:
  * SearchDialog -> s.g.s.searchdialog
  * SearchEditor -> s.g.s.searcheditor
* Consolidate SearchSlaves into one
* Consolidate QueryExecuters into one
* Import an enum and an interface from kiwi
* Move stoqlib.gui.base.columns into stoqlib.gui.columns
* Move HintedEntry into stoqlib.gui.widgets
* Move SearchFilterButton into stoqlib.gui.widgets
* Move LazyObjectList into stoqlib.gui.widgets

Change-Id: I1bc40b533f1953205aee633b47fbe655542d7568
Merge "Move search from kiwi"