enables the parsing of time Intervals YYYY-YYYY in the search Text
the timeInterval will only be parsed if the timeslider is not activated

improve stability
- check for presence of filter attribute year with dummy query
- year filter is not applied global anymore
- time enabled layers can be combined with other layers in the feature request

autopep8 search.py

Add nosetest for timeInterval search
replace testquery with timeEnabled request parameter parsing
update nosetests
feedback, cleanup
feedback, cleanup
Merge branch 'dev_enable_timeInterval_search_squashed' of https://github.com/geoadmin/mf-chsdi3 into dev_enable_timeInterval_search_squashed
Merge pull request #539 from geoadmin/dev_enable_timeInterval_search_squashed

enables the parsing of time Intervals YYYY-YYYY in the search Text