Tranform score creation_time accoding timezone in summary report
Adjust window title in detailed report
Show spin when building results on admin report page
Select only useful data

Relates to #301
Make one 'joined' query instead of many small queries

Relates to #301
Remove 'Translated (raw)' column from Project/Language activity table
Avoid many small queries

Relates to #301
Fill href attribute for month-selector items in admin report page