Fix WordUtils.containsAllWords missing words across line breaks

[alhudz]

Port of apache/commons-lang#1732 to Commons Text, as requested by @garydgregory.

containsAllWords builds the per-word regex .*\b<word>\b.* and runs it with matches(), but compiles it without Pattern.DOTALL, so . never matches a line terminator. Since matches() has to consume the whole input, a word sitting on a different line than the surrounding .* can reach is never found.

Repro: WordUtils.containsAllWords("foo\nbar", "bar")
Expected: true (bar is present as a whole word)
Actual: false
Fix: compile the pattern with Pattern.DOTALL so the leading and trailing .* span line breaks. The \b anchors are unchanged, so single-line results and the documented examples behave the same and no false positive is introduced.

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[garydgregory]

Thank you @alhudz , merged 🚀