[api2] add account creating and deleting apis (used by admin only)
[api2] custom defined HTTP status code does not reside in rest_framework.status module, remove the status namespace
[api2] add serializer for validating fields when creating new account
[api2] change to return object list when listing accounts
[api2] Update accounts api handlers
Merge branch 'swpd-master'
[api2] A few improvments on account api
[api2] simplify account serializer
rm 'has_subdir' check for accessible repos to fix a bug

fix bug for repo with no dir initially
Merge pull request #81 from swpd/master

minor code cleanup
[sub-lib] redesigned it: redesign 'share', no sync ...
* no 'sub-libraries' at 'myhome'
* don't create event when create sub-lib
* no 'sync'
* 'syncable-share' --> 'private share', no second popup
[sub-lib] improved ui & fixed bug for private-share
merge 'create_sub_lib' into 'check_sub_repo'; improved file/dir share js code
Change hashcompat to hashlib to depress warning
Modified sub repo
Show file size on share link page, and fix file share bug in readonly library
Fixed brand css and sharing message
Change favicon.ico to favicon.png
Modified starred table
Fixed image prev/next bug in windows server