erlang-dired-mode

when you open dired mode buffer ,if a Emakefile are in current or parent
directory recursively , then `erlang-dired-mode' minor mode is enabled.

 I write a function named `erlang-create-project' ,it will create a Emakefile
 and a Makefile(copide from mochiweb.) and erlang standard project .

`erlang-compile-dwim'
 if Emakefile exists in project root directory ,call "make:all[load]"
 if not call `erlang-compile'
 with  prefix `C-u':
 if Makefile exists in project root directory ,call make --directory project-root-directory
 if not call default make command (maybe ks "make -k")