* lyxfunctional.h: delete compare_memfun and helper classes

* lyxfunctional.h: delete compare_memfun and helper classes
* xformsImage.C (loadableFormats): use bind, equal_to instead of
compare_memfun
* QLImage.C (loadableFormats): use bind, equal_to instead of
compare_memfun
* bufferlist.C (exists): use bind and equal_to instead of
compare_memfun
(getBuffer): ditto
* lyxtextclasslist.C (NumberOfClass): ditto

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@9183 a592a061-630c-0410-9148-cb99ea01b6c8