For String Algo's trim, documentation is misleading.

[Peter Pimley <peter.pimley@…>]

The documentation for String Algo's trim functions states:

When parsing the input from a user, strings usually have unwanted leading or trailing characters.

Is that strictly true? There's no reason for a string to have leading or trailing spaces from, say, getline, a UI component, or a parameter in a URL.

It's certainly true that they can contain unwanted characters. Maybe in some situations they often do, but I think usually is misleading.

[Marshall Clow]

(In [77343]) s/ususally/often/; Refs #6689

[Marshall Clow]

(In [78557]) Merged changes for Boost.Algorithm to release; Fixes #6596; Fixes #6689; Fixes #3215; Fixes #6840