Add outlining functionality to the Qt4 TOC dialog.

Add outlining functionality to the Qt4 TOC dialog.

The Toc dialog is not finished yet, there's some clean-up to do especially in select_adapdator which doesn't seem to work. This makes lyx crash when clicking on the Up, Down, In or Out buttons.

    * frontends/qt4/QTocDialog.[Ch]: add automatic slots

    * frontends/qt4/QTocDialog.[Ch]: add "enableButtons(bool)"

    * frontends/qt4/ui/QTocUi.ui: add pushbuttons

    * frontends/qt4/QToc.[Ch]: add move* methods.

The following Qt4 equivalent changes to revision r13521 are not done yet:
    * frontends/qt2/QToc.[Ch]: add move* method.
    (QToc::updateToc):
    (QToc::select): add code for TOC window positioning, and
    outlining methods

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@13530 a592a061-630c-0410-9148-cb99ea01b6c8