Continued implementation of forward-crcs, adopted new test runners

This fixes most of the remaining bugs (except one with multiple padding
commits + noop erases in test_badblocks), with some other code tweaks.

The biggest change was dropping reliance on end-of-block commits to know
when to stop parsing commits. We can just continue to parse tags and
rely on the crc for catch bad commits, avoiding a backwards-compatiblity
hiccup. So no new commit tag.

Also renamed nprogcrc -> fcrc and commitcrc -> ccrc and made naming in
the code a bit more consistent.

lfs.h

@@ -112,8 +112,8 @@ enum lfs_type {
     LFS_TYPE_SOFTTAIL       = 0x600,
     LFS_TYPE_HARDTAIL       = 0x601,
     LFS_TYPE_MOVESTATE      = 0x7ff,
-    LFS_TYPE_COMMITCRC      = 0x502,
-    LFS_TYPE_NPROGCRC       = 0x5ff,
+    LFS_TYPE_CCRC           = 0x502,
+    LFS_TYPE_FCRC           = 0x5ff,
 
     // internal chip sources
     LFS_FROM_NOOP           = 0x000,