minor, provide literals for special echs instants
chore, use portable keyword `inline'
minor, import initial concept of ranges
minor, provide range coalescing
Merge branch 'feat/range'

* feat/range:
  minor, provide range coalescing
  minor, import initial concept of ranges
  chore, use portable keyword `inline'
  minor, provide literals for special echs instants
chore, zap to latest sxe-compiler.m4
chore, stop checking for xiar manually (SXE_CHECK_CFLAGS does it for us)
Merge branch 'bld/configure'

* bld/configure:
  chore, stop checking for xiar manually (SXE_CHECK_CFLAGS does it for us)
  chore, zap to latest sxe-compiler.m4
cosmetics, move sorting code to the bottom
minor, provide echs_now()
Merge branch 'core/instant'

* core/instant:
  minor, provide echs_now()
  cosmetics, move sorting code to the bottom