Support separate encoding settings for file content and file paths in Perforce

Perforce can have problems with non UTF-8 compatible encodings used in file paths. Simple solution was provided as a result of this FE-6909 bug.

It is possible, that file paths are encoded in different encoding than content of the files. Current behaviour allow to set one for whole repository.

Encoding have to be set according to the file paths, otherwise Fisheye will be unable to index repository. In result content of the files can be not rendered properly:

Provide solution to choose different encoding only for file paths. It will allow to index non UTF-8 file names properly, but also render file content correctly.