Help Tab for Dashboard: List of Boxes is Off by 2 Boxes

[dougwrites]

The Content sub-section of the help tab for Dashboard > Home lists the checkboxes in Screen Options. The list is inaccurate in that it doesn't include the Welcome box (new in 3.3) and the Plugins box it lists is not available if the install is multisite (even if one is signed in as the Network Admin).

[dougwrites]

Adds description for the Welcome box checkbox; puts in a ternary to have Plugins in this list only if not a multisite install

[nacin]

current_user_can()

[ryan]

In [19919]:

Cap check help text. Add mention of Welcome box. Props dougwrites, nacin. fixes #19933

[nacin]

In [19920]:

Cap check help text. see #19933.