blame,shortlog: don't make local option variables static

blame,shortlog: don't make local option variables static

There's no need for these option variables to be static,
except that they are referenced by the options array itself,
which is static. But having all of this static is simply
unnecessary and confusing (and inconsistent with most other
commands, which either use a static global option list or a
true function-local one).

Note that in some cases we may need to actually initialize
the variables (since we cannot rely on BSS to do so). This
is a net improvement to readability, though, as we can use
the more verbose initializers for our string_lists.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>