Python: metadata on builtin funcs. Support python3.
All: move some fns to core. Major cleanup.

- Don't import/require core until step4.
- Define cond/or macros from step8
All: perf test, Makefile refactor, add *host-language*

Other:
- bash,make,postscript: quasiquote of vectors
- Fix Java slurp
- add time function to core.mal
    - switches on *host-language* for make time-secs vs time-ms
- Ignore */experiments directories
Ruby,Python,C#: readline history fixes. Ruby include path.
All: *ARGV* and *host-language*. Misc syncing/fixes.
Perl: add readline interface and step0_repl
Perl: add step1_read_print, types.
Tests: move optional features to end and print header.
Perl: add step2_eval.
Perl: add step3_env
Perl: add step4_if_fn_do

- Move string/printing tests to the bottom of tests/step4_if_fn_do
Perl: add step5_tco

- Make all warnings fatal/exceptions.
Perl: step6_file
Perl: add step7_quote
Perl: step8_macros

- Fixes to core.pl: concat
- Fixes to types.pl: _symbol_Q, Function apply
Perl: add step9_interop with type conversion.
Correct issue where readline bombs out if there's no existing history file.
Automatically install node modules if the directory doesn't exist.
Perl: add stepA_more.
Perl: add step9_interop test