add swp and DS_store to gitignore
add gravatar_for to users_helper
add gravatar to signed_in navbar
adjust the gravatar's position in the navbar
add gravatar to show page of user
add test for gravatar_for helper
add gravtastic gem
use the gravtastic to show user's gravatar
delete the users_helper file and the spec test
add compound datetime responsive width. close #188
adjust user profile css. close #211
add registration form in the new_user_session view
Merge branch 'issues_187_add_registration_form' of git://github.com/ywjno/19wu into ywjno-issues_187_add_registration_form
Merge pull request #216 from saberma/saberma-bug/188-compound-datetime-responsive

活动起止时间输入框宽度要适应小屏幕
after user sign in, redirect to previous page. close #187

add standalone registration page.
Merge branch 'master' of github.com:saberma/19wu
change register button color in user bar.
delete one resources because they're not need
Merge pull request #218 from ywjno/delete_not_need_resources

delete not need resources
extract out has_html_pipeline as gem

See https://github.com/doitian/has_html_pipeline