Clarified ambiguous test wording for arrays.js remove per issue #80

Clarifies ambiguous test wording for remove and removeWithoutCopy functions on whether to remove a single instance or all instances of a given value per Open Issue #80.

Before, wording was unclear in arrays.js tests for remove and removeWithoutCopy that the intent is not to remove a specific value, or a single instance of an value, but rather all instances of a value from an array. Now, it clearly states all instances.