extracted console command method definitions into basic DSL
refactored methods into XSemVer::Commandable and #param_or_error method
#help_text is now an instance method instead of a class method
renamed #param_or_error to #next_param_or_error and changed command prefix from 'run_' to '_run_'
renamed XSemVer::Commandable to XSemVer::DSL
XSemVer::DSL extends ClassMethods via .included method
added comments to DSL ClassMethods and InstanceMethods.
replaced class_eval for method aliasing with alias_method call
Merge branch 'meta', which refactors XSemVer::Runner and extracts the messy bits into the XSemVer::DSL module.
incremented version patch. version is now 3.3.3