hygiene, refactor hdr and ftr rendering (__render_hdr(), __render_ftr())

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, fix up user defined messages trivially (just up the streak counter)

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
chore, cosmetics, add some assertions to check_size() for fixc msg builder and mem diagnostics

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, hygiene, refactor key/value state machine into anal() and use it for both compressed and uncompressed messages

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, allow anal() parser to return the number of bytes successfully parsed

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, use res->pz to keep track of to-be-processed data in anal()

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, copy one more message field than needed to aid anal()'s cache

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Revert "minor, copy one more message field than needed to aid anal()'s cache"

This reverts commit 5c6cfdf74f5d807ca029564b778f8be152b3a52b.

Crashes regression tests.
fix, redo reverted patch with additional check for alloc'd field space size

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'feat/fixc-rndr' into next

* feat/fixc-rndr:
  fix, redo reverted patch with additional check for alloc'd field space size
  Revert "minor, copy one more message field than needed to aid anal()'s cache"
  minor, copy one more message field than needed to aid anal()'s cache
  minor, use res->pz to keep track of to-be-processed data in anal()
  minor, allow anal() parser to return the number of bytes successfully parsed
  minor, hygiene, refactor key/value state machine into anal() and use it for both compressed and uncompressed messages
  chore, cosmetics, add some assertions to check_size() for fixc msg builder and mem diagnostics
  minor, fix up user defined messages trivially (just up the streak counter)
  hygiene, refactor hdr and ftr rendering (__render_hdr(), __render_ftr())