Slay all of the warnings! (Root task)

(It is recommended you read this with good humor, like Think Geek)

While building Netbeans, a number of warnings show up. We should fix that.

For the sake of organization, we should probably open a new task for each module. This will be the root/umbrella task. The main project heads should take a look at this task and update it with official stuff.

We should probably slay warnings in this order:

1. Warnings that don't require changes to other modules (like API changes). Examples would be changing raw types to non-raw types or something that would cause another module to not build after the warning has be properly dealt with.
2. Warnings that Do require changes to other modules (see previous entry for examples)
3. Those evil warnings that don't leave any links behind. Here are some examples:

   warning: [options] bootstrap class path not set in conjunction with -source 1.7
   /Volumes/Data/Code/<snip>/incubator-netbeans/nbbuild/build/public-package-jars/org-netbeans-api-annotations-common.jar(org/netbeans/api/annotations/common/NonNull.class): warning: Cannot find annotation method 'when()' in type 'Nonnull': class file for javax.annotation.Nonnull not found
   warning: unknown enum constant When.ALWAYS
     reason: class file for javax.annotation.meta.When not found
   /Volumes/Data/Code/<snip>/incubator-netbeans/nbbuild/build/public-package-jars/org-netbeans-api-annotations-common.jar(org/netbeans/api/annotations/common/NullAllowed.class): warning: Cannot find annotation method 'when()' in type 'Nonnull'
   warning: unknown enum constant When.MAYBE
   /Volumes/Data/Code/<snip>/incubator-netbeans/nbbuild/build/public-package-jars/org-netbeans-api-annotations-common.jar(org/netbeans/api/annotations/common/CheckForNull.class): warning: Cannot find annotation method 'when()' in type 'Nonnull'
   warning: unknown enum constant When.MAYBE
   warning: Supported source version 'RELEASE_6' from annotation processor 'org.netbeans.modules.openide.util.NbBundleProcessor' less than -source '1.7'
   warning: No processor claimed any of these annotations: org.netbeans.api.annotations.common.NullAllowed,org.netbeans.api.annotations.common.CheckForNull,org.netbeans.api.annotations.common.NonNull

 The following guide-lines should be followed while slaying warnings:

• You shall make every effort to resolve the warning without suppressing it. This may involve one or more of the following (non-inclusive):
  • Adding a new variable so assignments are not done to method parameters
  • Adding a variable followed with an "assert var != null" to let the IDE know that it can't be null
  • In the second pass, breaking APIs so raw types and such are not used if possible
• You shall suppress the warning on the smallest scope possible. Why? Warnings exist for a reason. They are there to tell you that you did something wrong, unless that was your intention and you know what you are doing. That is what @SuppressWarnings is for. If (heaven forbid) you suppress all warnings in a class file, you may be (figuratively) slain, so DON'T!
• The following (in my opinion) is a good way to suppress a warning on a line:

@SuppressWarning("unchecked")
Object shush = bar = (Foo<Bar>)foo;

• You may want to add dummy return values to some void methods to enable suppression via the above method.
• If you do suppress a warning, and it is not obvious why it was suppressed, document it! Leave a comment that says why it was suppressed. The following is an example:

//the following is intentional
//the method is expected to return an constant array
@SuppressWarnings("OverridableMethodCallInConstructor")
List<Foo> shush = ImmutableList.copyOf(getSupportedTypes());

I think that is all for now...