* jn/make:
Set datarootdir in config.mak.in
Quote all calls to GIT_CONF_APPEND_LINE
Typofix in configure.ac comment.
configure.ac vertical whitespace usage cleanup
autoconf: Checks for some programs
autoconf: Checks for libraries
autoconf: Checks for some library functions.
autoconf: Checks for typedefs, structures, and compiler characteristics.
autoconf: Preparing the way for autodetection
Copy description of build configuration variables to configure.ac
Teach make clean about configure and autoconf
autoconf: Use autoconf to write installation directories to config.mak.autogen