#9 PlugletLoader should refer to MANIFEST.MF in Jar files

[T.J. Willis]

The pluglet loader loops through all the files in a dir that
end with ".class" or ".jar" then uses the ClassLoader to
try to load each of these classes. For example, if it sees

MyNeatPluglet.jar

it will try to load the class MyNeatPluglet.class from that
Jarfile.

This causes a problem if a developer wants to have his
pluglet in a package structure. I.e. if the class
net.sourceforge.frodo.pluglets.MyNeatPluglet was in
MyNeatPluglet.jar, PlugletLoader wouldn't be able to find
it.

This could be fixed by using the "main-class" attribute of
a Manifest file. I.e., if MyNeatPluglet.jar had a manifest
file that read:

Manifest-Version: 1.0
Created-By: 1.4.0 (Sun Microsystems Inc.)
Main-Class: net.sourceforge.frodo.pluglets.MyNeatPluglet

Then PlugletLoader could get that value and pass it to
the ClassLoader.

This would also allow media resources to be stored in
the package structure and reduce the possibility of
naming conflicts there.