[svn-r29759] Purpose: Code improvements

Description:
    - Changed object in catch statements to reference
    - Replaced old-style casts or reinterpret_cast with static_cast
    - Removed unused name H5Library::need_cleanup
    - Removed Exception::printError from documentation
Platforms tested:
    Linux/32 2.6 (jam)
    Linux/64 (platypus)
    Darwin (osx1010test)

c++/src/H5IdComponent.cpp

@@ -207,7 +207,7 @@ IdComponent& IdComponent::operator=( const IdComponent& rhs )
 	    // Note: a = b, so there are two objects with the same hdf5 id
 	    // that's why incRefCount is needed, and it is called by setId
 	}
-	catch (Exception close_error) {
+	catch (Exception& close_error) {
 	    throw FileIException(inMemFunc("operator="), close_error.getDetailMsg());
 	}
     }