Update 02-identifiers-names-and-scopes.md

Fixed typo.
Update 03-types.md

Fixed typo.
Update 03-types.md

Inserted missing word "bounds".
Update 04-basic-declarations-and-definitions.md

Corrected the claimed outcome of the example in the section on repeated parameters. The example method sum sums up the _squares_ of the arguments.
Update 06-expressions.md

Inserted two missing instances of the word "the".
Corrected "invokeDynamic" to "applyDynamic".
Update 08-pattern-matching.md

Elided superfluous "a".
Corrected "no" to "not".
Update 10-xml-expressions-and-patterns.md

Changed two wrong plurals to singulars, and inserted a comma in an enumeration of alternatives before the last "or".
Update 12-the-scala-standard-library.md

Changed "in" to "by the".
Update 04-basic-declarations-and-definitions.md

Reverted the claimed result values of the example in the section on repeated parameters and changed the code of the example method instead.
Merge pull request #4039 from roberthoedicke/2.11.x

Minor spelling corrections and fix of the claimed outcome of the examples in the section on repeated parameters