NEW: math/gap

pkg/DESCR:
GAP is a system for computational discrete algebra, with particular
emphasis on Computational Group Theory. GAP provides a programming
language, a library of thousands of functions implementing algebraic
algorithms written in the GAP language as well as large data libraries
of algebraic objects.

Some things to note:

* The distfile, work dir, actual version string are all slightly
different: 4r8p10, 48, 4.8.10, that's why there's all this ${V}
munging.

* There is a test that apparently checks if our cwd is in the source
code, that's why I have a do-test instead of just using
TEST_TARGET. This way, the tests report no errors at all.

* I'm not an expert with autotools, I noticed that the build was using
-lreadline instead of -lereadline, so I just used sed to change it
around in some files, maybe there's a better way to do it.

* I noticed that the OpenBSD config.site has the line:

> ac_cv_func_timer_create=${ac_cv_func_timer_create=yes}

Isn't this wrong? OpenBSD doesn't have timer_create, right? gap
checks HAVE_TIMER_CREATE in some files and uses timer_create. To get
it to compile, I just changed the #if HAVE_TIMER_CREATE to #if 0,
but maybe I missed something? Is there a way to turn off using
config.site?

I was able to run the test suite on amd64 and sparc64 and got no
warnings (make test):

> #I No errors detected while testing

--
Kaashif Hymabaccus
GPG: 3E810B04