timezone() object: prep work
Merge branch 'master' into master-timezone-def

Conflicts:
	grammar/lexer.l
	grammar/rainerscript.h
new tzinfo config object -- permits to define time zone offsets
make datetime parser use new tzinfo infrastructure

also do some additons/modifications to infrastructure
fix cosmetic mem leak in tzinfo infrastructure

it's cosmetic, because it happens only during shutdown, so the OS
clean up a microsecond later in any case. But good to solve this
for valgrind AND future extensions.