change "\\" path style to "/"

Debian Linux Testing amd64, Minecraft 1.7.10, Forge 1208
When \\ style is used on Linux (and MacOS X should also work this way) - game creates wrong file in wrong location, filename becomes "1.7.\bluepower\partIds\partIds.txt" - and backslashes here are not directory delimiters, they are correct characters in the filename.
Using "/" should make everything ok.