Merge branch 'jk/maint-config-param' into maint

* jk/maint-config-param:
config: use strbuf_split_str instead of a temporary strbuf
strbuf: allow strbuf_split to work on non-strbufs
config: avoid segfault when parsing command-line config
config: die on error in command-line config
fix "git -c" parsing of values with equals signs
strbuf_split: add a max parameter

diff --cc config.c
Simple merge

diff --cc strbuf.c
Simple merge

diff --cc strbuf.h
Simple merge