Added setPath() and getPath().

Also fixed a major typo!
Added --options-file.

Allows to read the options.txt from a different file. Well, actually
this will only copy the given file over the options.txt in the Minecraft
directory.
Fixed not setting options if --texture-pack is not specified.
Added isRead() to determine if the file was read.
Refactored the working with the options.txt file.
Help text is now read from a text file in the jar.
Clean up formatting of help text.
Simple line break.
Added short notice about order of parameter-execution.
Updated parameter-section.
Path will now always be absolute.
Fixed wrong output when the options.txt could not be read.
I got that backward...
If an option does not exist, it will now print an error message instead
of failing.
Pushed version 0.12.