config: introduce git_parse_maybe_bool_text

config: introduce git_parse_maybe_bool_text

Commit 9a549d43 ("config.c: rename git_config_maybe_bool_text and export
it as git_parse_maybe_bool", 2015-08-19) intended git_parse_maybe_bool
to be a replacement for git_config_maybe_bool, which could then be
retired. That is not obvious from the commit message, but that is what
the background on the mailing list suggests [1].

However, git_{config,parse}_maybe_bool do not handle all input the same.
Before the rename, that was by design and there is a caller in config.c
which requires git_parse_maybe_bool to behave exactly as it does.

Prepare for the next patch by renaming git_parse_maybe_bool to ..._text
and reimplementing the first one as a simple call to the second one. Let
the existing users in config.c use ..._text, since it does what they
need.

[1] https://public-inbox.org/git/xmqq7fotd71o.fsf@gitster.dls.corp.google.com/

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>