Handle the moving gnc-hooks to src/engine.

[Derek Atkins]

Log Message:
-----------
Handle the moving gnc-hooks to src/engine.

	* src/core-utils/Makefile.am
	  Removed gnc-hooks to src/engine.
	* src/core-utils/gw-core-utils-spec.scm:
	  Removed gnc-hooks
	* src/engine/gnc-hooks.[ch]:
	  gnc-hooks are here, so it can deal with QofEntity handling.
	  Changed the API to take a GFunc and a cbarg.
	* src/engine/gw-engine-spec.scm:
	  added gnc-hooks wrapper

Tags:
----
gnucash-gnome2-dev

Modified Files:
--------------
    gnucash:
        ChangeLog
    gnucash/src/core-utils:
        Makefile.am
        gw-core-utils-spec.scm
    gnucash/src/engine:
        Makefile.am
        gnc-hooks.c
        gnc-hooks.h
        gw-engine-spec.scm