from pull request 853

from pull request 857

from pull request 852

from pull request 859

from pull request 846

from pull request 855

from pull request 858

from pull request 843

from pull request 845

from pull request 848

from pull request 849

- now user can fork two or more times from one original project.

from pull request 850

The accept button's url was not set correctly, cause it doesn't use '@'.

Cause:
There is no a if clause for Group page setting button.

Solution:
Add a if clause for the setting button.

Cause:
A wrong argument is passed to OrganizationUser.isAdmin().

Solution:
It is changed to correct one.

- determine the appropriate type of comment thread, depending on whether
  the code range is given or not.