Log Message:
Update R-gtools to 2.5.0

gtools 2.5.0
------------

New features:

- Add checkRVersion() function to determin if a newer version of R is
  available.

- Deprecated assert() in favor of base::stopifnot

Bug fixes:

- Fix bug in binsearch() identified by 2.6.0 R CMD CHECK

Other changes:

- Improve text explanation of how defmacro() and strmacro() differ from
  function().

- Update definitions of odd() and even() to use modulus operator
  instead of division.

gtools 2.4.0
------------

- Add binsearch() function, previously in the genetics() package.

gtools 2.3.1
------------

- Add ask() function to prompt the user and collect a single response.

gtools 2.3.0
------------

- Update email address for Greg

- Add new 'smartbind' function, which combines data frames
  efficiently, even if they have different column names.