Move single instance check logic into SingleInstanceChecker.py
Merge pull request #460 from LipuFei/clean-instancechecker

Move single instance check logic into one file
cleanup Category.
Cleanup.
Remove imports.
Restore callback(args, kargs)
Restore callback(...).
Remove show_permid_shorter.
cleanup
cleanup
fix
fix
More cleanup.
fix
fix
Remove MultiHTTPServer
Remove unicode.
Merge pull request #459 from LipuFei/cleanup

Cleanup