Patch for supporting controls in ldbadd/ldbmodify and ldbdel

[Matthieu Patou]

Hello,

Please find attached 2 patches for really supporting controls in 
ldbadd/ldbmodify and ldbdel as before the controls where not transmitted 
to ldb_xxx

I put also some unitest to check that when controls are specified they 
are really sent to the ldb_xx core function.

Please note that although that controls are less used for this functions 
than for ldbsearch there is always some cases when it can be intresting 
to have them (ie. when trying to reproduce a bug triggered by control 
use ...).

Matthieu