Fix compiler error and warnings (clang v3.4)

    * src/common/nmv-scope-logger.cc: Fix "warning: assigning field to
    itself"
    * src/common/nmv-str-utils.cc: Fix "warning: 'va_start' has
    undefined behavior with reference types"
    * src/common/nmv-str-utils.h: as above.
    * src/common/nmv-ustring.cc: as above.
    * src/common/nmv-ustring.h: as above.
    * src/confmgr/nmv-gconf-mgr.cc: Fix compile error.
    * src/dbgengine/nmv-i-var-list-walker.h: Fix include guard.
Fix glade 3 warnings

     * src/persp/dbgperspective/nmv-open-file-dialog.cc: vbox_file_list
     now a Gtk::Box. It was a Gtk::VBox. Gtk::VBox is now deprecated.
     * src/persp/dbgperspective/ui/findtextdialog.ui: Fixed "targets
     Gtk+ 2.6" warning by loading and saving file with glade 3. Use
     GtkBox instead of deprecated GtkVBox and GtkHBox.
     * src/persp/dbgperspective/ui/openfiledialog.ui: Likewise.
     * src/persp/dbgperspective/ui/proclistdialog.ui: Likewise.
     * src/persp/dbgperspective/ui/savedsessionsdialog.ui: Likewise.
     * src/persp/dbgperspective/ui/setbreakpointdialog.ui: Likewise.
     * ui/locatefiledialog.ui: Likewise.
     * ui/workbench.ui: Likewise.
Add .gitignore

    * .gitignore: New file. Ignore generated files.
UI selection widgets expand to use available space

    * src/persp/dbgperspective/ui/openfiledialog.ui: File selection
    widgets expand to use available space. Previously when the "Select
    from Target Executable" radio button was selected the selection
    widget displayed only one line (running on Ubuntu 14.04).
    * src/persp/dbgperspective/ui/proclistdialog.ui: Process list widget
    now expands to use available space. Previously the widget was only
    high enough to show the column titles.