Fails on pages where title markup is present but are not titles

[alex]

Consider the following markup:

= The Sandbox =

== Section 1 ==

{{{#!td
Table cell for title examples:
=== Title example ===
  {{{
  (line above prevents from messing up the markup; please ignore)
}}}

== Section 2 ==

Content for section 2.
}}}

It is rendered as this:

(image)

Titles (sections) are numbered as follows:
 * The Sandbox: `section=1`
 * Section 1: `section=2`
 * Section 2: `section=3`

However, the plugin is confused by the markup `=== Title example ===` included in the middle of the `#!td` element, and edition is done on ''Title example'' when ''Section 2'' is edited.

This behavior is easily reproducible by trying to edit a section on the WikiFormatting page of Trac version >=0.12 (where such title markup syntax examples are included).

[alex]

Example rendered.