icedtea7: New package

Free Java environment based on OpenJDK 7.0 and the IcedTea project.
icedtea: Add update script
icedtea: Workaround javaws/web plugin start-up error

This is a workaround to avoid the error: "java.io.IOException: RSA premaster
secret error".

In Java Web Start and the Java web plugin, there seems to be a Java policy
that prevents untrusted code from being loaded, and (probably for security
reasons) it doesn't like the files in the JDK's lib/icedtea/jre/lib/ext
directory to be symlinks.

Worked around it by copying those files instead of symlinking them.
npapi-sdk: New package

NPAPI-SDK is a bundle of NPAPI headers by Mozilla.
icedtea7_web: New package

Java web browser plugin and an implementation of Java Web Start.
Merge branch 'u/icedtea' of git://github.com/wizeman/nixpkgs

icedtea7, icedtea7_web: New packages