Improve the load/loadLibrary documentation.

Also improve the exception detail message for the default case.

Experience with third-party app developers is that the current documentation
is unhelpful and the current exception detail message is misleading. If we
didn't have to use the existing ClassLoader API, we could actually list the
exact pathnames we'd tried.

Change-Id: I31e1980addf34d6ada6a112949801c970f73bd2b
2 files changed