bugzilla-update.xml, to avoid warnings.
r=LpSolit, a=LpSolit

Bug 520948: Use Bugzilla->feature and feature_enabled everywhere instead of checking if modules are installed
Patch by Max Kanat-Alexander <mkanat@bugzilla.org> r=LpSolit, a=LpSolit

2nd attempt to fix bug 414726: Bugzilla::Update never updates bugzilla-update.xml if the file already exists locally - Patch by me r=mkanat

Bug 414726: Bugzilla::Update never updates bugzilla-update.xml if the file already exists locally - Patch by FrÃdÃric Buclin <LpSolit@gmail.com> r=mkanat a=LpSolit

Bug 378672: Use of uninitialized value in numeric comparison (<=>) at Bugzilla/Update.pm line 178 - Patch by FrÃdÃric Buclin <LpSolit@gmail.com> r/a=mkanat

Bug 350112: Error about "data/bugzilla-update.xml" being unreadable - Patch by FrÃdÃric Buclin <LpSolit@gmail.com> r=kevin.benton r=mkanat a=LpSolit

Bug 371727: One week is too long to wait for an update notification - Patch by FrÃdÃric Buclin <LpSolit@gmail.com> r/a=mkanat

Bug 367654: Param('upgrade_notification') eq 'development_snapshot' should catch release candidates too if no development snapshot is available - Patch by FrÃdÃric Buclin <LpSolit@gmail.com> r/a=mkanat

Bug 343294: Update notification does not work through an HTTP proxy - Patch by Cedric Caron <cedric.caron@citycable.ch> r=LpSolit a=justdave

Bug 328186: checksetup.pl should display the version of Bugzilla - Patch by Rémi Zara <remi_zara@mac.com> r=mkanat a=justdave

Patch By Max Kanat-Alexander <mkanat@bugzilla.org> r=LpSolit, a=justdave

Bug 330487: Automatic Update Notification for Bugzilla - Patch by Frédéric Buclin <LpSolit@gmail.com> r=mkanat a=justdave