Correct the $number argument description in get_terms() to reflect that an empty string or 0 will return all possible results, not -1.

Previously, it was noted that -1 would return all possible results. However, as the value of `$number` is passed through `absint()`, -1 would actually be converted to 1, thereby producing unexpected results.

Props iandunn.
Fixes #31526.

Built from https://develop.svn.wordpress.org/trunk@31638


git-svn-id: http://core.svn.wordpress.org/trunk@31619 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.2-alpha-31637';
+$wp_version = '4.2-alpha-31638';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.