Minor fixes / changes

Allow user to specify timeout, set the timeout before trying to connect,
added error handling if the domain couldn't be resolved
Minor cleanup
Scan last port in range, validate user input

The last port in the range specified by the user will now be scanned.
Perform basic checks to make sure the user entered a host and port range
Print strings differently
Merge pull request #1 from jtf323/master

Minor fixes / changes