Split "Upgrade" tools into new section

[johnjamesjacoby]

bbPress's database upgrades deserve their own section under "Tools."

They are unique in a few ways:

• You only really need to run them once
• They don't "Repair" anything, really
• As we point more users to important upgrades, a dedicated page is a better experience
• Large forums are unique, in that these types of upgrades will more frequently require monitoring than WordPress traditionally will

Maybe more importantly, I've already done all the work here (and it confirmed my suspicions) so let's do it.

[johnjamesjacoby]

In 6279:

Tools: Introduce new "Upgrade Forums" tools section.

• Uses some awesome trickery to reuse as much of the "Repair Forums" API as possible
• Introduces a few new functions to handle the output of the new screen
• Removes hard-coded referencs to bbp-repair page, to allow usage on any relevant page (including new bbp-upgrade)
• Makes components & overhead lists smarter, and only includes items relevant to the current view

Fixes #3052.

[johnjamesjacoby]

In 6280:

Tools: Map bbp_tools_upgrade_page capability to minimum admin capability. See #3052.

[johnjamesjacoby]

In 6281:

Tools: Separate wp_usermeta clean-up from database upgrade routines.

Clean-up should be run after upgrades, not during. This way all results can be verified by the admin.

See #3052.

[johnjamesjacoby]

In 6282:

Tools: Break tools.php up into separate files. See #3052.

[johnjamesjacoby]

In 6934:

Tools: allow repairs to also be pending.

This commit makes Repairs work like Upgrades, allowing for repair tools to also be pending. It adds a $type parameter to a few functions to allow grouping or separating, depending on the count context.

See #3052.

[johnjamesjacoby]

In 6935:

Tools: reduce the number of calls to bbp_is_large_install().

This commit refactors the update code to only call bbp_is_large_install() once, a function which ironically enough is costly to call on very large installations, so calling it 3 times defeats the purpose, but calling it one time is the minimum requirement to defer upgrades & repairs for keymaster interaction.

See #3052.