* exifr is used for most tags now

* New timestamp handling, removed exif-parser, date supported for png

* Removed offset from testhelper. It's optional

* explanations

* Feature/timestamps (#3)

* preparing for further timestamp test

* Added more test and fixed offset calculation bug

* Revered old dimension test, added new timestamp tests, some bug fixes

* Renamed png-test because faces overrule keywords

…This fixes the png-test

Added recognition of the offset value in the UI. It will be displayed if available.

Caveat: Search will not take offset into account. A new year's picture taken in Sydney the 1st of January 2019 00:15:00 GMT+11, is technically taken in 31st of December 2018 in UTC. Therefore this picture won't show of in seaches where the after: parameter is set to 1st of january 2019.

This is both correct and wrong at the same time.

UTC-wise it is correct, local time it is not correct. I guess most people would find local time most untuitive, so there is room for improvement of the search. :)

* effective storage of offset

* added comments to searchmanager.ts fixed linting error in utils