Remove pry and rspec-longrun from Gemfile.

These are already listed in the gemspec as development dependencies and pulled into the Gemfile from there.

This stops a bundler warning about gems listed more than once.
README - Minor typo correciton

* Correct gem package
Merge pull request #198 from cjfuller/fix_double_pry_dep

Remove pry and rspec-longrun from Gemfile.
Merge pull request #201 from duggiefresh/doug-fix-readme

README - Minor typo correction
Implemented NMatrix#data_pointer method to get the data location in
memory. Fixed ordering of dense structure members in nmatrix.h to match
design.
Merge branch 'master' of github.com:SciRuby/nmatrix
Fixed bug which was causing rake spec to run specs twice.