update for new Gyazz.com

新しいGyazzのAPI用に色々と修正しました
バージョンもv1.0.0に上げました

- use bundler style gem template
- delete Manifest.txt, PostInstal.txt
- delete pkg directory
- update .gitignore
- convert README.rdoc -> README.md
- add LICENSE.txt
- fix Makefile
- add Gemfile and Gemfile.lock
- add dependency "json" gem
- use "httparty" gem
- Gyazz::Wiki#pages, Gyazz::Page#text, Gyazz::Page#data
- Gyazz::Page#access, Gyazz::Page#modify
- Gyazz::Page.text="page body"
- Gyazz::Page#related_pages