Fix shared ptr docs for ptr == 0.
Improve null pointer docs.
Fix referenced nullptr_t ctor.
Fix deprecation message

Signed-off-by: Daryl Haresign <github@daryl.haresign.com>
Import work from ancient dev branch.
Typo in bslmf.txt
Review comments short of doc re-write
Revised doc for 'bslmf_detectnestedtrait'
Incorporate review comments.
Fix the license text for bdlb_randomdevice
[APPROVAL] pending/master/bdlb_randomdevice-license to master
[APPROVAL] pending/master/fix-deprecation-message-github-159-drqs-60427310 to master
Removed redundant `@DESCRIPTION`
[APPROVAL] pending/master/bslmf-nested-trait-doc-drqs-43473682 to master

Conflicts:
	groups/bsl/bslmf/doc/bslmf.txt
[APPROVAL] pending/master/issue-155-bslstl_sharedptr-docs-wrong-drqs-59827278 to master