Package hgk Tcl/Tk script in win32 installer
hgk script will be copied to Contrib/hgk.tcl
Update mercurial.ini file packaged in win32 installer
Update contrib/win32/mercurial.ini file with contrib/sample.hgrc
content and append contrib/mergetools.hgrc content during installation
Add Lee Cantey's installer icon to win32 installer
Add Lee Cantey's installer icon to contrib/win32 and update
mercurial.iss accordingly
notify: fix neglect of custom headers set via template
e981725da3fe introduced a bug that discarded all custom headers.
Add custom header to test template.