Update @DESCRIPTION of bslalg.txt based on description used in ACCU-2013
Replace use of 'bsls_Assert' with 'bsls::Assert'
Remove use of BSLMA_SIZE_IS_SIGNED in 'bsltf_stdstatefulallocator'

Import internal commit e0882ce811b507c4beac1a981714616fe8f97b11
cosmetica

Import internal commit 1580260055f46d4fa1ec61e4449113b923c90461
more robust detection of endianness in bsls_platform.h
Clean up signed size_type artifacts in bsl implementation
Clean up signed size_type artifacts in bsl comments.
Clean up signed size_type artifacts in bsl test drivers.
[APPROVAL] pending/master/bsl-endianness-drqs39774236 to master
Remove unused enum from bslstl_allocator test case 4.
[APPROVAL] pending/master/fix-package-prefix-use-bsls_exceptionutil-drqs40786629 to master
remove test-driver compilation error in cpp11

Import internal commit 2454d6bdcfd0e2f30d444c5e9403fecfe6ce467b
Fix build issue

Import internal commit 104bb0a67e2749cb30e97faac3419d77aa7c5ce0
[APPROVAL] pending/master/fix-rbtreeutil-cpp11-drqs39482124 to master
Move type traits to end of files

Import internal commit 507d68e9fcaa0cc1fdb5934ce0e12011366a74fd
[APPROVAL] pending/master/bslstl-traits-to-bottom-drqs-39302717 to master
#defined -> #define
[APPROVAL] fix-nightly-build-drqs41179688 to master
[APPROVAL] pending/master/bsltf_stdstatefulallocator-fix-warnings-drqs-40234657 to master
[APPROVAL] pending/master/bslalg-doc-fix-drqs-40276480 to master