add support for `.` current path

[FXTD-ODYSSEY]

add . support so that the mod file still can work with maya environment variable MAYA_MODULE_PATH

[FXTD-ODYSSEY]

helloWorld,mod could be write like this

+ helloWorld 0.0.1 .

If you add current repo path into MAYA_MODULE_PATH enviroment variable, that will work without helloWorld.mel dropped. That's convience for some pipeline situation.