beautifygraph: change the current commit symbol
The existing "circle with vertical fill" character renders as full width in
many terminals making the beautified symbols have uneven size. Additionally,
the proposed "fisheye" character is the logic 'active' version of the current
merge symbol, "bullseye."
Differential Revision: https://phab.mercurial-scm.org/D9678
$ hg init
$ echo 123 > a
$ hg add a
$ hg commit -m "first" a
$ mkdir sub
$ echo 321 > sub/b
$ hg add sub/b
$ hg commit -m "second" sub/b
$ cat sub/b
321
$ hg co 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ cat sub/b 2>/dev/null || echo "sub/b not present"
sub/b not present
$ test -d sub || echo "sub not present"
sub not present