Merge branch 'jk/upload-pack-hook'

"upload-pack" allows a custom "git pack-objects" replacement when
responding to "fetch/clone" via the uploadpack.packObjectsHook.

* jk/upload-pack-hook:
upload-pack: provide a hook for running pack-objects
t1308: do not get fooled by symbolic links to the source tree
config: add a notion of "scope"
config: return configset value for current_config_ functions
config: set up config_source for command-line config
git_config_parse_parameter: refactor cleanup code
git_config_with_options: drop "found" counting

diff --cc Documentation/config.txt
Simple merge

diff --cc cache.h
Simple merge

diff --cc config.c
Simple merge

diff --cc upload-pack.c
Simple merge