Add check for random port (fix #453)
Improve random port check.
Add debug info.
Fix.
Simplify the check.
Small change.
Check images, add wxthread warnings, small improvement.
Lazy load for other images, change to getImage().
Merge pull request #454 from LipuFei/add-rnd-port-check

Add random port check
Merge pull request #452 from LipuFei/clean-gui-image

Clean GUI image