* lily/grob.cc (Grob): idem. Plugs mem leaks.

* lily/grob.cc (Grob): idem. Plugs mem leaks.

* lily/context.cc (Context): unprotect key from ctor.

* lily/parser.yy (lilypond_header_body): copy previous
$globalheader if present.

* lily/ly-module.cc (LY_DEFINE): rename ly:import-module to
ly:module-copy

* scm/page-layout.scm (marked-up-headfoot): remove old functions.

* scm/titling.scm: remove old titling functions

* scm/page-layout.scm (marked-up-headfoot): create header/footer
field from user-supplied markup

* scm/titling.scm (marked-up-title): create title via
user-specified markup.

* lily/ly-module.cc (LY_DEFINE): use ly_module_lookup(). This does
not have side-effect of creating variable stub.