CLockedWorkUnit destructor may throw exception

Code using CLockedWorkUnit assumes that the destructor can throw an exception. This needs to be reviewed, because for C++11 onwards this causes the program to terminate.

In particular, EclAgent has a function updateWorkunit(). Some methods rely on the destructor to commit changes to the workunit in Dali, rather than by calling commit().

(The CLockedWorkUnit destructor is making a call to _unlockRemote() defined in CDaliWorkUnit.)