framework: update checkout.

Submodule framework ec92a1e..12c10e5:
  > hooks/fancy: call handle_output_{create,destroy} from print_stack_{push,pop} and check for falling edge properly.
  > scripts/shell: runner: allocate unique fd for passing stages from lister.
  > hooks/fancy: allocate unique fds for original stdout and stderr.
  > hooks/fancy: handle_output_{create,destroy}: fix detaching output handler from stdout.
  > scripts/globals: add backtrace function.
  > hooks/fancy: reduce impact of passing stderr via handler by doing this only between BUSY and DONE/FAILED lines.
  > hooks/fancy: handle_output: play nice to `set -e`: use if statement instead of $?.
  > hooks/fancy: report_success, report_fail: deduplicate code.
  > hooks/fancy: handle_output: ignore TERM/HUP/INT signals.
  > Revert "hooks/fancy: disable handle_output for the time being."
  > hooks/fancy: disable handle_output for the time being.
  > hooks/fancy: handle_output: trap exit signals.
  > hooks/fancy: do not run more than one post-process thread.
  > hooks/fancy: handle_output: do not be confused by leading whitespace of the 'nested block indented' lines.
  > hooks/fancy: let the first framework instance tell others that we're OK for fancy output.
  > hooks/fancy: add an experimental output post-processing thread to merge adjacent BUSY and DONE/FAILED lines.
  > hooks/fancy: print_prefix_text: use PRINT_COLORIZE_TEXT instead of COLORIZE_TEXT to avoid name conflicts.
  > hooks/fancy: print_prefix_text: add missing stderr redirection.
  > hooks/fancy: rewrite.
  > scripts/globals: report(): bikeshed a bit.
  > scripts/globals: sanitize log/err/notice prefixes a bit; add report_warn().
  > scripts/globals: add report_done() as alias to report_success().
  > scripts/globals: clarify check_decl() inapplicability to check variables.