Tidy up "fbegin.inc" XHTML

"id" must be a unique attribute.
Tidy up "pkg_mgr_install.php" XHTML

While using the widescreen theme, when you update the firmware or add a
new package the TEXTAREAs are side-by-side which doesn't look neat.
Add BR tag between TEXTAREA
Tidy up "interfaces.widget.php" XHTML

Remove duplicate closing TR tag
DIV tag cannot be enclosed in a B (bold) tag
Change class and style
Tidy up "gateways.widget.php" XHTML

Remove invalid "summary" attribute from TD tag
Tidy up "diag_dns.php" XHTML

Tidy up the "=" sign properly!
Remove "=" sign from INPUT tag
Change alignment to the "middle" of the TD tag
Add missing closing FONT tag
Tidy up "status_rrd_graph.php" XHTML

"id" attributes cannot start with a numeric character, so change "8hour"
to "eighthour" and "4year" to "fouryear".
Merge pull request #1277 from ExolonDX/branch_master_01
Merge pull request #1278 from ExolonDX/branch_master_02
Merge pull request #1279 from ExolonDX/branch_master_03
Merge pull request #1280 from ExolonDX/branch_master_04
Merge pull request #1281 from ExolonDX/branch_master_05
Merge pull request #1282 from ExolonDX/branch_master_06
Correct speeling as reported by: Phil Davis via github
Fix #3866 Firewall Log Filtering

on master
Merge pull request #1284 from phil-davis/patch-17