Improve prepare script
Improve prepare script

- Do not crash the script before all temporary changes have been rolled back
- Replace ALL occurrences of ~
- Use relative paths to import modules from node_modules

bholloway/sass-loader,Updater/sass-loader,mcanthony/sass-loader,gabriel-laet/sass-loader,dtothefp/sass-loader,bebo/sass-loader,mcanthony/sass-loader,bholloway/sass-loader,stevemao/sass-loader,bebo/sass-loader,stevemao/sass-loader,jtangelder/sass-loader,gabriel-laet/sass-loader,jorrit/sass-loader,Tol1/sass-loader,jorrit/sass-loader,jtangelder/sass-loader,dtothefp/sass-loader,Tol1/sass-loader,Updater/sass-loader