Fix qtcreator install and make it easier

First fix qtcreator install. Right now the wget runs -o (lowercase) which sets the log file. This actually creates two files qtcreator-package.tar.gz(which is just a download log) and qtcreator-package.tar.gz.1 which is the actual qtcreator package (which I think is not intended). Changed the command to -O (uppercase) to write the file to the location specified.

Second included a simple install script to install qtcreator. So new people do not need to manually unpack tar and know the location.

Also updated the README to reflect the changes.