There still seem to be quite some number of users with MSIE 8 and 7
coming to hosted Weblate.

fixes rb#22
fixes rb#21
fixes rb#20
fixes rb#19
fixes rb#18
fixes rb#17
fixes rb#16
fixes rb#15
fixes rb#45
fixes rb#46
fixes rb#47
fixes rb#48
fixes rb#49
fixes rb#50
fixes rb#51
Signed-off-by: Michal Čihař <michal@cihar.com>