Remove cmStdString from developer examples
docs: Enforce .at() guideline

It is used in the following places:

    Source/CPack/WiX/cmCPackWIXGenerator.cxx:117

introduced in:

    commit 85baac1503c638756211ba07c4c25128e6d3d845
    Author: Nils Gladitz <gladitz@scivis.de>
    Date:   Wed Oct 3 16:08:49 2012 +0200

    CPack: Add a WiX Generator (#11575)

It's the only use of std::vector::at(), so enforce the guideline.
docs: Update std::string::append usage guidelines

Usage of std::string::append has been around for a while:

    Source/CTest/cmCTestSubmitHandler.cxx:448

introduced in:

    commit 61b488021e7ac0321238ba1ba491478d58163b23
    Author: Andy Cedilnik <andy.cedilnik@kitware.com>
    Date:   Thu Jan 16 12:30:02 2003 -0500

        Improve submtitting using http

However, the Borland compiler does not like the iterator-range signature
of std::string::append, so explicitly mention that usage.
docs: Remove std::set::find == std::set::end guideline

It has been in use for a while in multiple places including:

    Source/CPack/cmCPackDebGenerator.cxx:429

since:

    commit 12ba1e9b208a25a8d4b5a97177e1fd6e4d4e5afa
    Author: Alexander Neundorf <neundorf@kde.org>
    Date:   Fri Mar 28 20:23:01 2008 -0400

        BUG: fix packaging of files installed to absolute paths, works only when
        used with SET(CPACK_SET_DESTDIR "ON")

and:

    Source/CPack/cmCPackPackageMakerGenerator.cxx:993

from:

    commit b2f041f6a899b2592477c98da0d060cc7c983a91
    Author: David Cole <david.cole@kitware.com>
    Date:   Wed Jul 30 13:28:17 2008 -0400

        BUG: Fix issue #7414 - do not crash when given components with circular dependencies. Thanks to Doug Gregor for the patch.

Other locations:

    Source/CPack/WiX/cmCPackWIXGenerator.cxx:883
    Source/CPack/cmCPackNSISGenerator.cxx:540
    Source/CTest/cmCTestMultiProcessHandler.cxx:476
    Source/CTest/cmCTestTestHandler.cxx:854
    Source/CTest/cmCTestTestHandler.cxx:864
    Source/CTest/cmCTestTestHandler.cxx:895
    Source/cmAuxSourceDirectoryCommand.cxx:65
    Source/cmExportBuildFileGenerator.cxx:281
    Source/cmGeneratorExpressionEvaluator.cxx:754
    Source/cmGlobalNinjaGenerator.cxx:535
    Source/cmGlobalVisualStudio7Generator.cxx:283
    Source/cmGlobalXCodeGenerator.cxx:1272
    Source/cmLocalGenerator.cxx:1583
    Source/cmMakefile.cxx:1550
    Source/cmQtAutoGenerators.cxx:1341
    Source/cmSourceFileLocation.cxx:97
    Source/cmSourceFileLocation.cxx:98
    Source/cmSourceFileLocation.cxx:176
    Source/cmSourceFileLocation.cxx:181
    Source/cmTarget.cxx:571
    Source/cmTarget.cxx:1168
    Source/cmTarget.cxx:1754
    Source/cmTarget.cxx:1982
    Source/cmTarget.cxx:2094
    Source/cmTarget.cxx:4448
    Source/cmXCodeObject.h:65
    Source/cmXCodeObject.h:70
docs: Enforce std::algorithm implicit cast guideline

There were only two instances (out of many) where it wasn't followed, so
enforce the rule.
docs: Remove std::set::insert(begin, end) guideline

Usage of this has been around:

    Source/cmComputeLinkDepends.cxx:874
    Source/cmComputeLinkDepends.cxx:944

introduced in:

    commit 816ee0f83cd9775e3b378fe3b074efe06d6b29a6
    Author: Brad King <brad.king@kitware.com>
    Date:   Wed Aug 27 10:21:57 2008 -0400

        ENH: New link line item ordering algorithm

also:

    Source/cmFindCommon.cxx:266
    Source/cmFindCommon.cxx:475

from:

    commit 1221581aa8de2b4bb06e09894940dba6ff90caa1
    Author: Todd Gamblin <tgamblin@llnl.gov>
    Date:   Thu Aug 12 15:20:47 2010 -0700

        Teach find_* commands to ignore some paths

and more.
docs: Enforce size_t usage
Merge topic 'dev/update-style-guidelines' into next

f011e703 docs: Enforce size_t usage
672aa130 docs: Remove std::set::insert(begin, end) guideline
844f49b8 docs: Enforce std::algorithm implicit cast guideline
19c9bead docs: Remove std::set::find == std::set::end guideline
fd2f6f22 docs: Update std::string::append usage guidelines
9bb8ff67 docs: Enforce .at() guideline
78146268 Remove cmStdString from developer examples