Intel compiler: add -isystem flag under Linux

This makes the SYSTEM keyword work with the Intel compiler
under Linux. AFAIK this is supported neither under Windows nor OSX.

Alex
Windows: Make file delete/rename retry configurable

Several CMake operations need to replace files in rapid succession.
This commonly fails on Windows due to filesystem lock behavior so
we have retry loops.  No matter how many times we retry or how long
we delay there will inevitably be someone with an environment that
needs more.  Make the retry count and delay configurable in the
Windows Registry keys:

 {HKCU,HKLM}/Software/Kitware/CMake/Config

in DWORD values

 FilesystemRetryCount = Number of tries
 FilesystemRetryDelay = Delay in milliseconds between tries

Leave the feature undocumented for now to see how it goes.
OS X: Escape path given to -isysroot flag

Ensure that paths containing spaces or other special characters are
escaped correctly on the command line.
CMake Nightly Date Stamp
cmake-mode.el: Add the ability to retrieve module help.
cmake-mode.el: Add help for variables/properties/complete. Factorize.
Ninja: Cache target-level flags

Instead of figuring out target flags per-source file, cache the flags
that are being used. This results in a *much* faster generate time for
Ninja.
Merge topic 'osx-sysroot-escape'

77b2e6f1 OS X: Escape path given to -isysroot flag
Merge topic 'dev/ninja-speedup'

26762e16 Ninja: Cache target-level flags
CMake Nightly Date Stamp
cmTarget: Don't try to get sources of an INTERFACE_LIBRARY.

An an assert to ensure this.
CMake Nightly Date Stamp
CMake Nightly Date Stamp
CMake Nightly Date Stamp
Small typo fix
Help: Fix typo

 binary_find -> binary_search.
include_directory: Add missing include.

The cmGeneratorExpression is used here, but the header for it is not
in the include heirarchy.  This would be a compile error if the file
were compiled as a standalone translation unit, but it is instead
used in a mini-unity-build by inclusion in cmCommands.cxx. The header
for cmGeneratorExpression happens to be included first, so the
compilation works fine.

IDEs do not know this however, and flag the use as an error.
cmGlobalGenerator: Remove unused variable.
Makefile: Fix comment indentation.
Kate: handle spaces in build dir

They need to be escaped in the json file... I'm quite
sure I tested this before, obviously I didn't test it
correctly.

Alex