add missing #undef
support IPv6 numeric address in the URL parser
update project settings
ignore *.xccheckout (see https://github.com/github/gitignore/blob/master/Objective-C.gitignore http://stackoverflow.com/questions/18340453/should-xccheckout-files-in-xcode5-be-ignored-under-vcs)
[refactor] prepare for adding more options
[refactor] extract protocol-specific initialization code as separate functions
implement configuration test mode `--test` (a.k.a. dry-run)
add minimum lib for server-starter support