include/: Removed redundant #include's.
include/: Removed redundant #include's (level = 2).
ext/, include/: Required Ruby version >= 1.8.7.
ext/, include/: #define RCLASS_SUPER.
ext/{common,ieee}.c: Get rid of RUBY_1_9_LATER.
Define version in lib/gsl/version.rb.
ext/extconf.rb: Use have_func for GSL functions.
ext/: Get rid of rb_gsl_config.h.
ext/{. -> gsl/}: Renamed
ext/gsl/extconf.rb: Final cleanup.