commit-patch: fix very important unterminate parenthesis in documentation that's been there since 2008

Two issues caused detection of buffers from patch filenames to fail:
  1. git uses a/some/file where cvs used some/file.
  2. (find-buffer-visiting) doesn't seem to work with relative paths.

Closes #14

README.md: Add Installation and Development sections, removing IPC::Run from Prerequisites since we're fatpacked now

Changes-By: lintian-brush
Fixes: lintian: out-of-date-standards-version
See-also: https://lintian.debian.org/tags/out-of-date-standards-version.html

Changes-By: lintian-brush
Fixes: lintian: uses-debhelper-compat-file
See-also: https://lintian.debian.org/tags/uses-debhelper-compat-file.html

Changes-By: lintian-brush
Fixes: lintian: package-uses-old-debhelper-compat-version
See-also: https://lintian.debian.org/tags/package-uses-old-debhelper-compat-version.html

Changes-By: lintian-brush
Fixes: lintian: missing-vcs-browser-field
See-also: https://lintian.debian.org/tags/missing-vcs-browser-field.html

Changes-By: lintian-brush
Fixes: lintian: homepage-field-uses-insecure-uri
See-also: https://lintian.debian.org/tags/homepage-field-uses-insecure-uri.html

Changes-By: lintian-brush
Fixes: lintian: insecure-copyright-format-uri
See-also: https://lintian.debian.org/tags/insecure-copyright-format-uri.html