Fix resouce mapping issue on Windows
Fix resouce mapping issue on Windows

Prior to this change, resource mapping configuration was incomplete
since it only started with the "file://" scheme. On windows, this lead
to mapping issues since the OS matched "file://C:/folder" as FTP URLs.

This prefixes paths with "/" to make sure that all OS treat this as
paths.

Fixes #366 #457

spring-io/sagan,eonezhang/sagan,martinlippert/sagan,mbateman/sagan,lowtalker/sagan,dkushner/sagan,dvaughn555/sagan,gregturn/sagan,rwinch/sagan,martinlippert/sagan,dlizarra/sagan,amit-siddhu/sagan,martinlippert/sagan,andriykonoz/sagan,seoilhyun/sagan,lowtalker/sagan,dkushner/sagan,spring-io/sagan,seoilhyun/sagan,vizewang/sagan,vizewang/sagan,dlizarra/sagan,TabberGit/sagan,TabberGit/sagan,dvaughn555/sagan,spring-io/sagan,vizewang/sagan,spring-io/sagan,dharmaraju/sagan,TabberGit/sagan,dvaughn555/sagan,rwinch/sagan,amit-siddhu/sagan,garylgh/sagan,garylgh/sagan,martinlippert/sagan,gregturn/sagan,amit-siddhu/sagan,dlizarra/sagan,andriykonoz/sagan,lowtalker/sagan,dsyer/sagan,mbateman/sagan,BHASKARSDEN277GITHUB/sagan,lowtalker/sagan,dharmaraju/sagan,vizewang/sagan,dharmaraju/sagan,yhj630520/sagan,garylgh/sagan,BHASKARSDEN277GITHUB/sagan,rwinch/sagan,eonezhang/sagan,mbateman/sagan,dkushner/sagan,eonezhang/sagan,dvaughn555/sagan,yhj630520/sagan,dsyer/sagan,garylgh/sagan,amit-siddhu/sagan,andriykonoz/sagan,dsyer/sagan,dsyer/sagan,BHASKARSDEN277GITHUB/sagan,gregturn/sagan,yhj630520/sagan,seoilhyun/sagan,dlizarra/sagan,dkushner/sagan,dharmaraju/sagan,seoilhyun/sagan,eonezhang/sagan,BHASKARSDEN277GITHUB/sagan,andriykonoz/sagan,yhj630520/sagan,rwinch/sagan,mbateman/sagan,TabberGit/sagan