Removing "import" statements from AIDL-generated .java files.

AIDL generates unnecessary "import" statements. These cause warnings
within Eclipse when the default Eclipse warnings settings are used.
This is inconvenient since the generated .java files are not
editable. Some pesky organisations have a zero-warnings policy
too, so there's no option but to fiddle with the Eclipse settings.

This patch ensures that all usages of class names within the
generated code are fully-qualified. In practice, they were nearly
all fully-qualified already. And this patch also removes the
generation of the import statements, since they are redundant
if we're using fully-qualified names everywhere.

This should fix issue 43 in the Google Code Android issues tracker.
http://code.google.com/p/android/issues/detail?id=43

I would appreciate if somebody who knows exactly how 'aidl'
works could confirm that there's no reason 'import' statements
would have been necessary except for the bits I've fixed. (I think
unqualified names were used much more frequently in early versions
of aidl, which might explain why import statements are generated
so eagerly).