bitbake: hob: progress bar changed to busy cursor when you open log file

bitbake: hob: progress bar changed to busy cursor when you open log file

-the first implementation for this bug used a progress bar, that is shown
during open file process; it revelead that the progress bar stops earlier
-now I have implemented using gtk.show_uri() method, that shows itself a
busy cursor when it opens a file;
-deleted the code for the first implementation

[YOCTO #2997]
(Bitbake rev: 09d1c4c2db124104b9da460547b20a2c2ff07bb3)

Signed-off-by: Cristiana Voicu <cristiana.voicu@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>