Resolve warnings about unused variables.
load_command: Deprecate and document pending removal

This command works only when building projects using the same
architecture as the running CMake binary.  Since it was introduced
CMake has learned macro() and function() to add commands, and the
execute_process() command to launch advanced external computations.

Add a RunCMake.load_command test to verify the warning appears.
Squish: fix new squish_v4_add_test() macro

The OUTPUT_NAME target property only returns something if it has been
explicitely set. So use LOCATION, and extract the filename from that.

Alex
Documentation: Correct typos and grammar
Documentation: Clarify some command descriptions

- file(WRITE): add configure_file() decoupling hint
- function(): definitely mention PARENT_SCOPE
- include_directories(): mention possible results of SYSTEM setting
- macro(): mention scope specifics of function()
- message(): improve SEND_ERROR / FATAL_ERROR docs, since people said it's not obvious
Documentation: Clarify configure_file behavior
OS X: Warn about known SDK breakage by Xcode 3.2.6

Xcode 3.2.6 is known to break the SDK Library/Frameworks layout.
Detect and warn about this case to tell users to fix their system.

Reported-by: Matthew Brett <matthew.brett@gmail.com>
KWSys 2012-11-08 (3b17de34)

Extract upstream KWSys using the following shell commands.

$ git archive --prefix=upstream-kwsys/ 3b17de34 | tar x
$ git shortlog --no-merges --abbrev=8 --format='%h %s' df32fa6f..3b17de34
Brad King (1):
      3b17de34 SystemInformation: Do not dereference NULL ifa_addr

Change-Id: I2aecf9978d1f66ed021f47620d176a3837bc2ea3
Merge branch 'upstream-kwsys' into update-KWSys
Resolve warnings about used enum values in switch blocks.
Resolve warnings about shadowing parameters and local variables.
Resolve ambiguity warning regarding use of && and ||.

This is not ambiguous to the compiler, but it may seem ambiguous to
the reader.

From reading 3a53005f (Build object library targets in VS), 5484550a
(Detect and set Unicode character set in VS 10), and 9e01aefd (VS:
Add support for WinRT project properties (#12930)), this appears to
be the intentional semantic.
Remove references to ancient and removed parts of the code.

This file came from ITK, and probably came from python before that.

This commit fixes a warning about the unused _PyPopenProcs variable.
Enable some compiler warnings when building CMake.

The warnings are enabled for now only when using GCC 4.2 or later.
It may be possible later to also enable them when building CMake
with clang.  Don't duplicate the compiler flags if already set.
ccmake: Allow DEL key in first column

Change test if DEL key is allowed from 'curcol > 0' to 'curcol >= 0', as
deleting forward is reasonable in the first column (and probably
expected by users to work).

Support for DEL was first added in commit b3b43508 (BUG: fix for 6462,
delete key should delete the current char, 2008-08-19).  The commit
appears to have copied the original logic from the backspace code so the
old 'curcol > 0' logic was accidental rather than intentional.
Merge topic 'fix-13604-ccmake-del-key'

d424de4 ccmake: Allow DEL key in first column
Merge topic 'deprecate-load_command'

d2d4398 load_command: Deprecate and document pending removal
Merge topic 'compiler-warnings'

d06a9bd Enable some compiler warnings when building CMake.
Merge topic 'MakeSquish4Work'

b58fd65 Squish: fix new squish_v4_add_test() macro
Merge topic 'doc-fixups'

fa04673 Documentation: Clarify configure_file behavior
07d5e4b Documentation: Clarify some command descriptions
965de97 Documentation: Correct typos and grammar