ExternalProject: Set LABELS property to targets

This is useful for using CDash subprojects.
ExternalProject: Set FOLDER property to targets

This is useful when using the USE_FOLDERS global property
KWSys 2014-05-05 (f3a36760)

Extract upstream KWSys using the following shell commands.

$ git archive --prefix=upstream-kwsys/ f3a36760 | tar x
$ git shortlog --no-merges --abbrev=8 --format='%h %s' 8b085635..f3a36760
Brad King (2):
      1979c02d hashtable: Poison operator= on internal node type
      f3a36760 SystemInformation: Include backtrace APIs whenever we use them

Change-Id: Ic90b29e4fbae139ab6c8bd7355661759153e0aa7
Merge branch 'upstream-kwsys' into update-kwsys
InstallRequiredSystemLibraries: MBCS MFC is optional on VS 12 (#14903)

The MBCS (Multi-Byte Character Set) has been deprecated with VS 2013,
and MSVC no longer ships with an MBCS-version of MFC by default.
However, it can be downloaded as an add-on.

Teach InstallRequiredSystemLibraries to install the MBCS MFC only
for VS < 12 or if it happens to exist on the system.
Xcode: Find fallback SDK if one matching the OS version doesn't exist.

For example if one installs Xcode 4.6 on OS X 10.9, it doesn't contain
a 10.9 SDK, so fallback to the next newest version which, in this case,
happens to be a 10.8 SDK.

This fixes bug #14572.
OS X: Use -iframework for system framework directories

Just like -I flag has its -isystem counterpart which marks an include
directory as a system directory and prevents unwanted warnings, on Apple
systems there is -iframework -- a system directory replacement for -F.
Use this flag to implement include_directories(SYSTEM) for frameworks.
Merge topic 'update-kwsys'

edad0369 Merge branch 'upstream-kwsys' into update-kwsys
397bccba KWSys 2014-05-05 (f3a36760)
Merge topic 'ExternalProject_labels'

93730bb3 ExternalProject: Set FOLDER property to targets
39ef8046 ExternalProject: Set LABELS property to targets
Merge topic 'InstallRequiredSystemLibraries-vs12-mfc'

c0a6646d InstallRequiredSystemLibraries: MBCS MFC is optional on VS 12 (#14903)
Merge topic 'xcode-sdkroot'

5dfe9b7d Xcode: Find fallback SDK if one matching the OS version doesn't exist.
Merge topic 'osx-iframework'

1bed75a5 OS X: Use -iframework for system framework directories