Tests: prettify Makefile
vim-patch:7.4.260

Problem:  It is possible to define a function with a colon in the name.  It
          is possible to define a function with a lower case character if a
          "#" appears after the name.
Solution: Disallow using a colon other than with "s:".  Ignore "#" after the
          name.

https://code.google.com/p/vim/source/detail?r=6bc874e4789a0f912b4fd6b23afecf19d80b1605