Update to 2020.01

Changelog (main changes):

• fix bugs in n:MIN, n:MAX, a:index-of, s:WHITESPACE
• removed uses of raw nga bytecode from standard library
• added optimized implementations of the standard library functions
• reduced the overall size slightly
• added retro-lookup(1) to search the tags file created by retro-tags(1)

PR: 243373
Submitted by: Charles Childers <crc@forthworks.com>
Event: Brussels DevSummit 2020