Add a command line option to override internal resources.

Some of the internal resources of jpackage (other than the Localized I18N properties files) may be over-ridden by files places in ./package/<platform>/

for windows this currently includes: icon_inno_setup.bmp, javalogo_white_48.ico, template.iss, template.jre.iss, template.jre.wxs, template.wxs, and WinLauncher.template .

There is some name translation required, for example if I run the following command:

jpackage create-installer exe \
--verbose --input input --output output/menu --name menu --icon config/awt.ico \
--win-menu --main-jar HiDPI.jar --class test.robot.RobotScreenTest --files HiDPI.jar \

if file ./package/windows/menu.iss exists, ./package/windows/menu.iss will be used instead of src/jdk.jpackage/windows/classes/jdk/jpackage/internal/resources/template.iss.

also if ./package/windows/menu.ico exists, it will be used instead of config/awt.ico (or instead of javalogo_white_48.ico when no --icon is given).

The bmp used in inno setup can be replaced either by adding package/windows/menu-setup-icon.bmp, or by modifying the appropriate line in ./package/windows/menu.iss

a post install script can be run for the exe installer by adding: ./package/windows/menu-post-image.wsf (even though there is no such default resource).

We need to clean up and document this functionality.
Instead of just checking for resources in ./package/<platform>, we should add a new command line option such as --custom-resources, which defines a path to find such overridden resources.