完善0.2.0功能

1.增加api显示
2.修复首页5秒刷新一次
3.优化后台算法
添加后台首页消息
修正api-v2版的一处url显示问题
修正返回url地址为全路径，并在首页增加相应的说明
	modified:   .gitignore
	modified:   Gemfile
	modified:   Gemfile.lock
	modified:   app/controllers/admin/api_controller.rb
	modified:   app/controllers/admin/application_controller.rb
	modified:   app/controllers/application_controller.rb
	modified:   app/views/layouts/admin.html.erb
	modified:   config/database.yml
	modified:   config/initializers/carrierwave.rb
修改carrierwave的asset_host
合并文件，过滤database.yml
过滤database.yml
修改gemfile
Merge pull request #1 from sapronlee/dev-v3.0

修改carrierwave的asset_host
修改文件application_controller.rb
Merge pull request #2 from sapronlee/dev-v3.0

修改文件application_controller.rb
Merge pull request #2 from howiloveyou/dev-v3.0

Dev v3.0
修改api_controller.rb
Merge pull request #3 from sapronlee/dev-v3.0

合并并修改api_controller.rb
去掉ImgSeek处理图片的流程代码，修改为自己的图片处理算法
Merge branch 'dev-v3.0' of https://github.com/howiloveyou/ImgSeek into dev-v3.0

Conflicts:
	app/controllers/admin/application_controller.rb
	config/initializers/carrierwave.rb
	.git/MERGE_HEAD

	modified:   .gitignore
	modified:   Gemfile
	modified:   Gemfile.lock
	renamed:    config/database.yml -> config/database.yml.default
	modified:   app/controllers/api/v2/pictures_controller.rb
	modified:   app/models/picture.rb
	modified:   app/models/scenic.rb
	modified:   config/initializers/default_settings.rb
	modified:   config/locales/admin.zh-CN.yml
更新API版本号为v3，并添加API使用说明。
Merge pull request #3 from howiloveyou/dev-v3.0

Dev v3.0