Process `--activate` flag on `language install` even if already installed

Actually return `false` when `$widget` is empty

Adapt license header so GitHub picks it up

Improve `wp menu location assign` command

```
Loading composer repositories with package information
Updating dependencies (including require-dev)
  - Removing mustangostang/spyc (0.6.1)
  - Installing mustangostang/spyc (0.6.2)
    Downloading: 100%

  - Removing phpunit/php-timer (1.0.8)
  - Installing phpunit/php-timer (1.0.9)
    Downloading: 100%

Writing lock file
Generating autoload files
```

Before:
```
require:
  - file1.php  - file2.php
```

After:
```
require:
  - file1.php
  - file2.php
```

Update Composer dependencies (2/27/2017)

Add missing line break in FeatureContext.php

Introduce `WP_CLI\Utils\basename()` for locale-independent basename()

Abstract `wp import` to a separate wp-cli/import-command package

Per the function comment "Environment values permit specific binaries to be indicated". Currently not possible as PHP_BINARY ***always*** present as defined constant (which can NEVER be overridden unless one uses runkit_extension; dated, not supported)

Like with other commands, info, update, run command, utilize WP_CLI::get_php_binary() in lieu of fixed PHP_BINARY constant.

Fix allowing env. values to permit specific binary

Update tests for WordPress 4.7.3

Abstract `wp db *` to wp-cli/db-command

This prevents adding Composer dependencies with known security vulnerabilities.

Resolves #3842

…names

Fix category, tag and term names missing in export

Adapt tests

Only add needed user when filtering by `--author`

Ensure post attachment meta is exported correctly