Enable to add extra single quote used by some Watcom tools.

Change-Id: I257bafd1c09c02642e0d793caf7461454bc4b04a

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.

ENH: check in almost building VMS stuff with VMSBuild directory since the bootstrap script will not work on VMS

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.

ENH: Improved escaping in kwsys/System.  Added escape of % for NMake.  Added escape of ; for the VS IDE.

ENH: Added more special unix shell characters that require quoting.  Added escaping of % as %% for shells inside mingw32-make.

ENH: Adding Shell_Flag_EchoWindows option to setup escapes for arguments to the native echo command in a shell.  This special case is needed to avoid adding quotes when passing text to echo in a native windows shell which does no command line parsing at all.

ENH: Re-implemented command line argument shell quoting to support several platforms with one code base.

ENH: Adding 'System' component of C sources to hold system tools written in C.  Moved windows shell command line argument escaping code to kwsysSystem_Windows_ShellArgument and kwsysSystem_Windows_ShellArgumentSize.