appropriate containers, remove misleading const qualifiers, reduce
repeated XML walking.
(nw) Groups aren't parameterised, so they aren't as useful as they could
be (yes, it's on my TODO list). However, it's already useful for
putting a common set of elements in multiple views, potentially at
different locations/scales. See intlc44.lay and intlc440.lay for
examples of the level of copypasta this can eliminate. Be aware that
groups with explicit bounds don't clip thair content, it's only used for
calucating the transform matrix.
Use standard uint64_t, uint32_t, uint16_t or uint8_t instead of UINT64, UINT32, UINT16 or UINT8
also use standard int64_t, int32_t, int16_t or int8_t instead of INT64, INT32, INT16 or INT8
