Finding nodes by content mimetype

All content type properties have an extended property to allow search by mimetype.
This will be extended to include the size of the content in the future.
所有内容类型属性都有一个扩展属性，允许按mimetype进行搜索。
这将在将来扩展到包括内容的大小。

To find all cm:abstract content properties of mime type ‘text/plain’:

@\{http\://www.alfresco.org/model/content/1.0\}content.mimetype:text/plain

Note: This extended attribute is not available for TEXT.mimetype as it may be made up of many different content types.
注意：此扩展属性不可用于TEXT.mimetype，因为它可能由许多不同的内容类型组成。