Log Message:
Changes 1.15:
* port to Perl 5.15.0, where the op type aelemfast has been split into
  aelemfast and aelemfast_lex
* test compatibility with Devel::CallParser

Changes 1.14:
* bugfix: never unhook peephole optimiser, because unhooking is liable
  to fail if anything else hooked it
* bugfix: revise check for dorassign opcode to cope with FreeBSD's
  mutant Perl 5.8 that has it
* test POD syntax and coverage