Plugin initialisation errors are app errors.

This happens if everything goes OK, but either the constructor
can't be injected or the constructor lobs an exception.

Both of these are some kind of app error, rather than user error.

Change-Id: I90ba613b9ecbbad0bf64df2b325667a0fa0076d1
Fixes-Issue: CLIENT-444
Reviewed-on: http://gerrit.dmdirc.com/3180
Reviewed-by: Greg Holmes <greg@dmdirc.com>
Automatic-Compile: DMDirc Build Manager
Update submodules: plugins (new commits)

plugins:
    652abcd Chris Smith <chris@dmdirc.com>
            DI the logging plugin.

            Gerrit: http://gerrit.dmdirc.com/3179

Change-Id: I0ff7e76888973114410776283481d859e77e1bd7
Update submodules: plugins (new commits)

plugins:
    d228ad6 Greg Holmes <greg@dmdirc.com>
            DI the DCOP plugin

            Gerrit: http://gerrit.dmdirc.com/3181

Change-Id: I1ca11c8449b9684c7fb6da182fcdf5024a6353f5
Update submodules: plugins (new commits)

plugins:
    539596b Greg Holmes <greg@dmdirc.com>
            Stop using PropertyDescriptor, it requries a getter/setter pair.

            Fixes-Issue: CLIENT-443
            Gerrit: http://gerrit.dmdirc.com/3177

Change-Id: I74fbc431311a4ee051982a002b46bcccb5a3089e