Feature request: Search-and-replace feature in the tag editor

[raindropsfromsky]

Rather than editing the ID3 tag of each track separately, sometimes it is much more convenient to search and replace tags.

For example,

1. A few tracks may have some data in their tags such as "track number", "year", "DiscNumber", or "Comment". I want to delete such spurious data.
2. I want to change the name of a singer wherever it appears.
3. I want to change the name of the genre for selected files.

Please provide such bulk editing facility.

What functions are required:

1. Global search and replace a value.
2. Global search and delete a value
3. Search a particular tag for a value, and replace it with another value.
4. Search a particular tag for a value, and delete it.
5. Let the user select specific files from search results, and conduct "search-and-replace" in those selected files only.
6. Let the user select specific files from search results, and conduct "search-and-delete" in those selected files only.