When viewing detailed count information through the usage of the
--all argument, extra arguments would be also passed to the
git shortlog command (probably to be used as revisions list)
This behaviour was introduced in commit 7a60cd1.
Unfortunately the --all argument itself is passed along and results
in the counts of all refs to be displayed
This commit removed the usage of extra arguments and thus only
display the counts of the current branch
Matching "):" in the end can match commit subjects by mistake i.e. if
commit subject ends with "):" too (e.g. linux project has one such
commit).
To avoid this and any similar problems print summary only (-s).
Restructure output to look exactly as it was before with awk.
Use git-rev-list and builtin --count option
$ time git log --oneline | wc -l
30613
real 0m0.858s
user 0m0.684s
sys 0m0.239s
$ time git rev-list --count HEAD
30613
real 0m0.416s
user 0m0.396s
sys 0m0.018s
