Relatively simple update to clean up some of the old naming in the `html.markup` world.
`FixedStringContent` is renamed to just `Text` and a new factory method `Text.of(CharSequence)` introduced. `StringContent` is renamed to `TextBuilder`. `StringContent` was the original type and is widely used; `FixedStringContent` was added much later, along with `Contents` to support shared reusable tree nodes. But most uses of `StringContent` do not need mutability, and most can be replaced with the lighter-weight `Text` class. This change is done, just leaving `textBuilder` to be used in `ContentBuilder` and `HtmlTree` which support the `add(CharSequence)` method. ------------- Commit messages: - JDK-8261665: Clean up naming of StringContent and FixedStringContent Changes: https://git.openjdk.java.net/jdk/pull/2556/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2556&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8261665 Stats: 584 lines in 41 files changed: 198 ins; 207 del; 179 mod Patch: https://git.openjdk.java.net/jdk/pull/2556.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/2556/head:pull/2556 PR: https://git.openjdk.java.net/jdk/pull/2556
