Doxygen version: 1.5.1

Problem:
According to the documentation of the LATEX_HEADER option, the special
command $title should be replaced with "the title of the page."

This is not the case; the string '$title' is inserted verbatim into
the generated refman.tex.

Discussion:
First of all, it is not clear what "the title of the page" means in
the context of LaTex output generation.  For HTML generation, $title
is expanded for HTML_HEADER and HTML_FOOTER text, and this can receive
the actual title of the current page.

For LaTeX generation, the expansion is performed only in one file,
refman.tex, at a time where only the title of the main page (if any)
is known.  But on the other hand, the name of the current chapter or
section appears already in the page header by standard LaTeX means.

Solution:
In principle, there are two ways to fix this bug:
1) Simply remove $title from the special commands that apply to
   LATEX_HEADER.  This requires just a documentation fix.
2) Let $title expand to the title of the main page.  This requires a
   minimal extension of the LaTeX generator.

The supplied patch implements the second solution.