[PATCH v2 3/7] log: add -P as a synonym for --perl-regexp

Add a short -P option as a synonym for the longer --perl-regexp, for consistency with the options the corresponding grep invocations accept. This was intentionally omitted in commit 727b6fc3ed ("log --grep: accept --basic-regexp and --perl-regexp", 2012-10-03) for unspecified future use. Make it

[PATCH v2 3/7] log: add -P as a synonym for --perl-regexp

Add a short -P option as a synonym for the longer --perl-regexp, for consistency with the options the corresponding grep invocations accept. This was intentionally omitted in commit 727b6fc3ed ("log --grep: accept --basic-regexp and --perl-regexp", 2012-10-03) for unspecified future use. Make it