pfSense

Restore id for cancel button to fix js error

While I'm touching this file, replace GET by POST

Deduplicate <form>, fixes #3864

Correct speeling as reported by: Phil Davis via github

Merge pull request #1282 from ExolonDX/branch_master_06

Merge pull request #1281 from ExolonDX/branch_master_05

Merge pull request #1280 from ExolonDX/branch_master_04

Merge pull request #1279 from ExolonDX/branch_master_03

Merge pull request #1278 from ExolonDX/branch_master_02

Tidy up "status_rrd_graph.php" XHTML

"id" attributes cannot start with a numeric character, so change "8hour"
to "eighthour" and "4year" to "fouryear".