Add 2nd optional parameter to HedgewarsScriptLoad. If false, its OK if file does not exist. Also, return true/false on success
# This file is used to override default values used by the Ant build system.
#
# This file must be checked in Version Control Systems, as it is
# integral to the build system of your project.
# This file is only used by the Ant script.
# You can use this to override default values such as
# 'source.dir' for the location of your java source folder and
# 'out.dir' for the location of your output folder.
# You can also use it define how the release builds are signed by declaring
# the following properties:
# 'key.store' for the location of your keystore and
# 'key.alias' for the name of the key to use.
# The password will be asked during the build when you use the 'release' target.