Builder support

Currently Kommander has bare bones builder support, which uses non-semantical format to add features and execute the said features. New format should look like so:

(new Kommander.Builder())
    .addCommand(Class<? extends Command>)
    .addProvider(Class<? extends Provider>)
    .build()

And while executing

kommanderInstance.getBuilder(Class<? extends Command>?)
    .addArgument(String modifier, Any value)
    .addArguments(String commandLine)
    .addArguments(Map<String, Any>)
    .build() //returns Command implementation which is chosen from either provided ones internally or via current builder
    .execute() // executes the built command

The build step is somewhat iffy and is up for discussion.