define WPLANG only for WP < 4.0
add tests to check if WPLANG is defined only for WP < 4.0
Merge pull request #1524 from rodrigoprimo/wplang

`wp core config` should define WPLANG only for WP < 4.0
Don't allow active language to be uninstalled
Merge pull request #1527 from wp-cli/1516-language-active

Don't allow active language to be uninstalled
Added new subcommands wp user term and wp post term
Improved tests, formatting and backwards compatibility for post / user term
Merge pull request #1528 from spacedmonkey/commandwithterms

Support listing, updating, and removing terms associated with posts and users
install-wp-tests.sh svn wget https wordpress.org

Use https for requests to wordpress.org   Fixes svn checkout currently failing using http like:

svn co --quiet http://develop.svn.wordpress.org/trunk/tests/phpunit/includes/
svn: E175002: Unable to connect to a repository at URL 'http://develop.svn.wordpress.org/trunk/tests/phpunit/includes'

github issue wp-cli/wp-cli#1529
Merge pull request #1530 from here/templates-install-wp-tests-sh-wordpressorg-https

Use https with curl and wget requests to wordpress.org
fix merge conflicts