BUG-1026: Better message when we fail lookup

This turns a NPE into a checkArgument(), such that we emit proper
diagnostic information.

Change-Id: I90c68fafde35cc28c9e9449a5984a7c42f1f467d
Signed-off-by: Robert Varga <rovarga@cisco.com>
(cherry picked from commit 0594a8f6d4d19ab1a61e6dadf843706d75dd670f)
BUG-1026: do not mask unexpected exceptions

This patch restructures the code such that we do not silently drop the
exception we may encounter during module info loading -- promote it
to an IllegalArgumentException.

This has the nice feature or also not masking any RuntimeExceptions we
may encounter.

Change-Id: I8a2c7108b589234c0c1350024dacb0d7f1ec4d72
Signed-off-by: Robert Varga <rovarga@cisco.com>
(cherry picked from commit 6964d6c9c5bc644f6a48b0235ea8e4ef7c9102db)
Merge "BUG-1026: Better message when we fail lookup" into stable/hydrogen
Merge "BUG-1026: do not mask unexpected exceptions" into stable/hydrogen