Make cppumaker work on top of unoidl/ instead of registry/, as a first step to
change all the various codemakers.

* API CHANGE: cppumaker no longer supports the -B switch, as that is meaningless
  with the new format.  When reading from an old-format .rdb file, /UCR is
  hard-coded as the prefix now.

* TODO: The new format does not yet support deprecation annotations, so the
  generated .hdl/.hpp files lack any SAL_DEPRECATED_INTERNALs for now.

* codemaker/typemanager.hxx is extended with access to unoidl/ functionality, so
  the various codemakers can use registry/ and unoidl/ in parallel for now.
  The access to registry/ functionality will be removed.  (Added small throwaway
  helper functions u2b/b2u to easily map between OString and OUString at the
  remaining seams for now.)

* Includes a selective revert of ba044b1e
  "remove needless forward rtl::OUString declarations" in those parts of
  codemaker, unodevtools, unoidl that were covered by this local
  work-in-progress patch; I would otherwise have hard a hard time re-applying
  it.

* The generated .hdl/.hpp files are mostly unchanged, except for a few minor
  things:

** Any SAL_DEPRECATED_INTERNALs are missing (see above).

** In comprehensive getCppuType definitions, some members were erroneously
   classified as TypeCalss_UNKNOWN.

** In comprehensive getCppuType definitions, some unnecessary calls like

     ::cppu::UnoType< ::sal_Int32 >::get();

   can be removed.

** For typedef sequence<X>, the .hdl file need not include X.hdl, but only needs
   to forward-declare it.

** Unnecessary includes for optional bases of interfaces can be removed.

** Some numbering of local variable names (sMethodName1, ...) has changed.

Change-Id: Icad98f248ac15177337f1b4ab709a755a8af6238