Support: Add expected support results for Safari 7 & IE11
Tests: fix Safari userAgent detection

(cherry-picked from 3f3f458974fe0bdccfe9042c9503fd2d03e2f6ff)
Tests: Fix appendChecked support value for Safari 5.1
Manipulation: Use textarea for missing IE defaultValue check

IE11 fixed the checkbox defaultValue issue but not textarea. Rather than
creating a new detect name I'm reusing the old one to protect anyone who
is unwisely using this externally. Re-fixing the defaultValue when it
doesn't need to be done is not a problem, so leave that code for IE11.

Fixes #14716
Closes gh-1495