FORMAT

HEADER
offset  size    desc
0       4       offset to CRC blob (8-aligned)
4       X       start of root table


TABLE (first is at pos X+4)
offset  size    desc
0       2       serialized field count (FC)                         // <-- start of vtable
2       2       max serialized field id                             // TODO do we need this?
4       2*FC    field ids of every field in memory order 
4+2*FC  4*FC    Corresponding field offsets (from table start)      // TODO Test interleaving offset/id, test 6-byte offsets
4+6*FC  X       start of first table field                          // <-- start of table contents


STRINGS & ARRAYS
offset  size    desc
0       4       length / count
4       X       content

FOOTER
offset  size    desc
X       X       CRC blob