Progress bar update as need. Fix float() error.

Fixed bug that was causing the TX rate to crash the program when completion
reaches 100%.

The updating of the progress bar was killing the CPU performance because it
was updating so often this was causing the Xorg process to have crazy high
CPU usage. By only updating if the percent completed would actually change
the program runs way faster and does not peg the CPU.
Merge branch 'master' of https://github.com/tbehan/mintstick