BUILD: mkrelease.sh: allow customization of the ChangeLog output filename
DOCS: avoid overhead-prone doxygen sections for changelogs, use h2 instead
DOCS: trim development changelog to show just branch merges
DOCS: start section "UI Definition Syntax"
DOCS: examples/: run tests on documentation examples
DOCS: allow documenting things as UNSTABLE, DISCOURAGED or DEPRECATED
RCORE: deprecate public MarkupParser use
RCORE: discourage public XmlNode use
DOCS: ignore selected doxygen issues and error out otherwise
DOCS: remove obsolete SHOW_DIRECTORIES
DOCS: apps: fix section link
RCORE: silence doxygen
UI: silence doxygen
UI: document can_focus and has_focus
DOCS: add brief data binding description
Merge branch 'docs'

* docs:
  DOCS: add brief data binding description
  UI: document can_focus and has_focus
  UI: silence doxygen
  RCORE: silence doxygen
  DOCS: apps: fix section link
  DOCS: remove obsolete SHOW_DIRECTORIES
  DOCS: ignore selected doxygen issues and error out otherwise
  RCORE: discourage public XmlNode use
  RCORE: deprecate public MarkupParser use
  DOCS: allow documenting things as UNSTABLE, DISCOURAGED or DEPRECATED
  DOCS: examples/: run tests on documentation examples
  DOCS: start section "UI Definition Syntax"
  DOCS: trim development changelog to show just branch merges
  DOCS: avoid overhead-prone doxygen sections for changelogs, use h2 instead
  BUILD: mkrelease.sh: allow customization of the ChangeLog output filename