Problem:    "..." used inconsistently in messages.
Solution:   Drop the space before " ...".

Problem:    No compiler warning for wrong format in vim_snprintf().
Solution:   Add printf attribute for gcc.  Fix reported problems.

Problem:    Clearing a pointer takes two lines.
Solution:   Add VIM_CLEAR() and replace vim_clear(). (Hirohito Higashi,
            closes #2629)

Problem:    Number of spell regions is spread out through the code.
Solution:   Define MAXREGIONS.

Problem:    No check for spell region being zero. (geeknik)
Solution:   Check for zero. (closes #2252)

Problem:    Some macros are in lower case.
Solution:   Make a few more macros upper case. Avoid lower case macros use an
            argument twice.

Problem:    Size computations in spell file reading are not exactly right.
Solution:   Make "len" a "long" and check with LONG_MAX.

Problem:    Possible overflow with spell file where the tree length is
            corrupted.
Solution:   Check for an invalid length (suggested by shqking)

Problem:    Modelines in source code are inconsistant.
Solution:   Use the same line in most files.  Add 'noet'.  (Naruhiko Nishino)

Problem:    spell.c is too big.
Solution:   Split it in spell file handling and spell checking.