change data directly in mysql for some tables

search-replace on tables that don’t contain serialised data can be
changed directly in mysql
Clarify method

See #1231
If the plugins directory doesn't exist, create it before installing
Fix copy pasta
Support for automagically creating the theme directory too
Allow updating core directly from a ZIP file

Previously, updating core from a ZIP file also required passing `--version`
Test coverage for permitting updates from file without specifying version
Merge pull request #1242 from wp-cli/update-from-zip

Allow updating core directly from a ZIP file
Fix silly copy and paste error again. `hello` exists in WP.org as `hello-dolly`
Need to register the theme directory after it's been created
Merge pull request #1238 from wp-cli/create-directory

Create plugins / themes directory if it doesn't exist
List meta for an object, demo commit
Special treatment for JSON, and tests that fail because meta_value isn't unserialized
Throw warnings if the plugin is already active
When a given theme is already active, provide a contextually appropriate message

Also prevents triggering of `switch_theme()` if the theme is already activated.
Messaging more consistent with the rest of `wp plugin`
Test cases for these warning messages
Merge pull request #1248 from wp-cli/already-active

Throw warnings if a plugin is already active
Network-only plugin check should only happen on multisite
Merge pull request #1250 from wp-cli/network-only

Network-only plugin check should only happen on multisite