Roll up of string changes for performance testing/improvement, and a couple API features supporting them.
String API changes:
Defining a tuning knob to control the heap growth policy (relapaces former 10% hardcode, downgraded to a default)
Implementing findFrom (allowing find-non-first); leaving find as find-first.
String implementation perf improvements:
Calling C-malloc directly instead of via CFA-alloc.
Replacings loops that copy with memmove calls.
Replacings loops that search for a value with memchr calls.
String perf testing realized:
Makefile supporting several prog-*.cfa, chosen by OPERATION value (implies prog.cfa changes to support the adjusted protocol)
Adjusting the starter/accumulater declarations in PEQ and PTA to behave consistently in cfa v cpp.
Adding tests: allocation, find, normalize, pass-by-val, pass-by-x.
Adding helper shell scripts for: generating flame graphs, collecting/crunching allocation stats using Mubeen's malloc wrappers
