Adjust isFile validator.
Merge pull request #15 from danielsoro/patch-1

Adjust isFile validator.
Change @Option value from String to String[]
Added two options to command
Removed duplicated for
Fixed problem with many option values. Thanks Jonathan Gallimore @jgallimore
Adjuste help and sufix option
Clean up
Fix completer problem
Improvement completer test
Improvement HelpTest
Merge pull request #17 from danielsoro/option-value

[Fix #3] Support multiple names for options - thanks Daniel!