UPDATE: fs_readDir + malloc bugfix, runtime changes

Hello again! Some minor fixes & changes with this update:

• A fix to fs_readDir, so it now properly null-terminates the directory name in the output struct
• A fix to malloc not being properly 8-byte aligned - this could cause issues with reading directories (as internally directory info table is allocated using malloc and has i64 fields)
• Builds are now published as "self-contained", which means they should no longer require separately downloading the .NET runtime. This should make Dreambox "just work" on machines that don't already have .NET installed.
• New "dev" builds are now available which launch a visible console output window. This is handy if you're a developer and would like to see log output more easily