Updates to subtitleConverter for easier use and Linux support

I added a few lines to the README to make compiling and running a bit more straight forward. 

I changed Pruebas.java so that the args list is using the correct indices, as well as modify the exception handling which seemed to be causing problems on compile (this included moving the output.close() to the STL "if" statement, rather than be a finally executed piece of code, as it only applies to STL).

I added a separate Convert.java which does pretty much the same thing as Pruebas, but when no args are given, prints out usage instructions.

In FormatASS and FORMATTML I removed a couple of characters which caused compiling problems on UTF8 system (in this case Ubuntu).

The only change you may not want to keep is in IOClass. I had to change the paths to use "/" instead of the escaped backslash "\\" as I am running in Linux rather than Windows.