Port code from the KWSys System_Shell APIs into cmOutputConverter.
Drop it from our copy of KWSys because upstream will drop it too,
and by doing it in this commit 'git blame' may have an easier time
connecting the history of the content.
This converts the KWSys license to a pure 3-clause OSI-approved BSD
License. We drop the previous license clause requiring modified
versions to be plainly marked. We also update the KWSys copyright to
cover the full development time range.
Add System_Parse_CommandForUnix to the KWSys System interface as a
utility to parse a unix-style command line. Move the existing
implementation out of ProcessUNIX. Add a flags argument reserved for
future use in providing additional behavior.
All KWSys C symbol names begin with the KWSYS_NAMESPACE defined at
configuration time. For ease of editing we write canonical names with
the prefix 'kwsys' and use macros to map them to the configured prefix
at preprocessing time. In the case of standalone KWSys, the prefix is
'kwsys', so the macros were previously defined to their own names.
We now skip defining the macros in the identity case so that the final
symbol names are never themselves macros. This will allow the symbols
to be further transformed behind the scenes to help linkers in special
cases on some platforms.