[ftinspect] Fix uninitialized memory issue and reference misuse.
- Properly initialize
FT_Bitmap
since it's a value type. - Fix the accident overwriting of the source bitmap when converting the bitmap format (only happens for
FT_PIXEL_MODE_GRAY2
andFT_PIXEL_MODE_GRAY4
) due to misuse of C++ reference. - Fix the crash when the
QImage
was failed to produce.
Fixes #23 (closed) .