Added SimpleFilePathConverter class.

Performs file path substitution using StringUtils.replace().
This is basically the same as UnixToWindowsFilePathConverter but doesn't
change '/' to '\'.
Merge branch 'gda-8.40' of ssh://dasc-git.diamond.ac.uk/gda/gda-common into gda-8.40
Merge branch 'gda-8.40'