Move default log file to g_Config.memCardDirectory/PSP/SYSTEM/Logs/ppsspp.log.
Disable default logging(--log still works fine), delete CommonPaths.h, and remove unused funcs in FileUtil.
Clean up FileUtil.h. Remove GetBundleDirectory(I searched master and nothing uses it either).
Merge pull request #4214 from thedax/adjustLogDirectory

Non-USING_GLES2 platforms: Move default log file location.