updated installer to use regkeys for 20sim 4.4
Merge commit 'db98019550417447546ca53a598deeabb892d5f5' into release

Conflicts:
	ide/product/src/main/resources/installer/destecs.nsi
Start parameterising the nsi script for use with the maven resource filter
Make the script for the crescendo install generate-able using maven.
See the comments in ide/product/pom.xml for how it works.