Fix reporting out of nested custom C-shaped blocks

REPORT now reports to the nearest lexical element expecting an input
(which may not be the block holding the REPORT statement, this lets you
REPORT out of nested FOR loops).
STOP THIS BLOCK behaves as it used to.
If you’ve been using REPORT instead of STOP THIS BLOCK, you should
migrate.
Treat REPORT blocks inside custom command definitions as STOP THIS BLOCK / IGNORE INPUTS

this also enables all existing FINCH blocks and other hardware
extensions again, which used the REPORT (HTTP://) pattern
Merge branch 'master' of https://github.com/jmoenig/Snap--Build-Your-Own-Blocks