Change QString formatting of negative numbers in non-base-10

For bases other than 10, negative numbers have been converted
to QString by casting them to an unsigned number and
converting that. Thus QString::number(-17, 16) returned
"0xffffffffffffffef", for example.
This patch changes the behavior so that
negative numbers are converted like positive numbers.
Additinally, this patch adds unit tests for QString::number.

[ChangeLog][Important Behavior Changes]
Changed QString::number(integer, base) for negative numbers
and bases other than 10 to return the string corresponding
to the absolute value, prefixed by "-".

Fixes: QTBUG-53706
Change-Id: I0ad3ca3f035d553860b262f5bec17dc81714d8ac
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

0 files changed, 0 insertions, 0 deletions