If note title contains "&" symbol, delete verification message breaks

[Shane Synan]

Description:
The "Really delete [title of note]?" warning dialog incorrectly shows the Pango markup instead of parsing it and formatting the text as bold when the title of note contains the "&" symbol.
E.g. <span weight ='bold' size='larger'>Really delete "Rhetoric - Allyn & Bacon Presentation"?</span>

How to reproduce:
* Create a new note in Tomboy
* Add the "&" symbol somewhere in the title of the note
* Press the delete button
* Note the incorrect dialog formatting

What should happen:
* The main dialog text is bold and larger, as seen whenever deleting a note without the "&" in the title.

Notes:
See the attached screenshots for the incorrect and correct formatting.

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: tomboy 1.8.0-1ubuntu1.1.1
ProcVersionSignature: Ubuntu 3.0.0-16.28-generic 3.0.17
Uname: Linux 3.0.0-16-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 1.23-0ubuntu4
Architecture: amd64
CheckboxSubmission: 535d52cf08b1e59fc90ec42e434fc960
CheckboxSystem: daed2f3d6643b4a84b4520a2427f8c2b
Date: Sun Mar 4 14:40:36 2012
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release amd64 (20100429)
SourcePackage: tomboy
UpgradeStatus: Upgraded to oneiric on 2011-11-20 (104 days ago)

[Alemann Massho (armistice-con-deactivatedaccount)]

I can verify this bug on the same version of Ubuntu and Tomboy that you have.

[Sebastien Bacher (seb128)]

Confirming the issue on precise

[Shane Synan (digitalcircuit)]

As an update, though it's low importance, I can confirm the dialog text still breaks on Ubuntu 13.10 with Tomboy 1.15.2.