Fix issue MR-85 - Microsoft .NET Framework warning

Fix issue MR-86 - Citrix GDI+ Error when screen is locked
Fix issue MR-299 - mRemoteNG crashes while using remotely (Windows XP remote desktop)
Change target .NET Framework to 3.0 instead of 2.0
Change ConDefaultUseCredSsp to be a User scoped setting instead of Application scoped.
Update copyright year in installer.
Updated translations with data from Crowdin.

Added translations for Spanish (Argentina), Italian, Portuguese, Chinese (Simplified).