Please describe the problem:
Task summary isn't sorted by utf8 collation keys.

Steps to reproduce:
1) login to en_US.UTF-8
2) launch Evolution
3) create some tasks (e.g. aaa, bbb, xxx and some with Latin accented characters
at the beginning)
4) click summary button on the top and try to sort tasks summary


Actual results:
Tasks with the accented characters should be sorted as those non-accented.

Expected results:
Tasks are not sorted correctly, tasks with the accented characters at the
beginning are sorted as a special characters.

Does this happen every time?
Yes.

Other information: