LaTeX: Use \ul (from the "soul" package) instead of \uline
* ox-latex.el (org-latex-text-markup-alist): Use \ul{...} for
underlining instead of \uline{...} as requiring the hyperref
package makes \uline{...} unusable on headline.
* org.el (org-latex-default-packages-alist): Add the "soul"
package.
Thanks to Konstantin Kliakhandler for reporting this.