Adds selftest for utf-8 encoding.

[test-fullautomation]

Hi Son, very good! Please add five tests:

1. import into utf-8 file "normal" data
2. import into utf-8 file another utf-8 file
3. import into "normal" file utf-8 file
4. create parameter where key and value have utf-8 data. Overwrite other existing value with ${utf-8 key}
5. like 4, but nested

Thank you, Thomas

[test-fullautomation]

Hi Son, please provide the requested additional tests. Thank you, Thomas

[namsonx]

Hello Thomas,

I have just added more unittest cases for utf-8 handling.

Thank you

[test-fullautomation]

Hi Son, there is a merge conflict in atest/jsonpreprocessor/jsonpreprocessor_unittest.py Please solve this. Thank you, Thomas

[namsonx]

Hello Thomas,

I have just resolved conflict of this pull-request.

Thank you, Son

[namsonx]

Hello Thomas,

I have just resolved the merge conflict, you can merge it now :)

Thank you, Son