[[ Valgrind ]] Use Memcheck macros to mark pooled MCValue buffers.
[[ Docs ]] Add a 'docs/specs/' directory.
[[ thirdparty ]] Update submodule to latest 'develop' branch.
Merge pull request #1440 from peter-b/misc-valgrindpools

[[ Valgrind ]] Use Memcheck macros to mark pooled MCValue buffers.
Merge pull request #1391 from peter-b/misc-unicodestring

libfoundation: Add accessors to add codepoints into strings.
Merge pull request #1482 from peter-b/docs-specsdir

[[ Docs ]] Add a 'docs/specs/' directory.
Merge branch 'origin/develop' of into feature-stackdir.
[[feature-stackdir]] Unquoted strings must start with a letter.

Unquoted strings are permitted to contain the character '-'.  However,
so are numbers.  To improve clarity, require unquoted strings to
always start with a letter, i.e. they must match
[a-zA-Z][a-zA-Z0-9_-]*.
[[feature-stackdir]] Add specification in Markdown.