Re-introduced contains, isAlphaNumeric and trim functions.
insert functions are back, same for isValidUtf8.
findSubstring is back
two of the replace functions are back
Improved performance of isMark(?)

isMark is used by nthCharacter functions and ought to be fast. I hope this improves efficiency by reducing cache-usage.
Added replace (string with string)
Consider non-minimal UTF-8 code points invalid.

Saw on unicode.org that non-minimal (or de-normalized) UTF-8 code points should be treated as invalid.
Added invalidUtf8 test.
Tine improvement in nextCodePointUtf8
Added replaceInvalidUtf8
Re-introduced lower, title and upper.
Implemented substring
Removed redundant and rejected files
Tidying
Moved Paths files back.
Added PathFilter
Various reorganizations
Added RawStrings
Added generic nextToken and prevToken functions
Removed GenericJoin.hpp (replaced by RawString.hpp)
Re-implemented various UnixPath functions.