Support decentralised pull-request workflow

[Rinat Shigapov]

Currently I can't do pull-requests from my fork to upstream repository. I configured fork and upstream repositories as origin and upstream remotes correspondingly. Upstream is used for master branch only. Other branches are pushed to the fork repository (origin).

I set remote=upstream in .stashconfig.yml. When I try to create pull-request I get an error about not existing branch in upstream repository. But the branch is in the origin.

[Евгений Баба]

Hi.

I also saw it. I fixed it in my PR. While this is not accepted, you can use my fork.

https://bitbucket.org/atlassian/stash-command-line-tools/pull-requests/25/fixed-check-special-repository-url

[Rinat Shigapov]

I managed to create pull-request from my fork when specified remote name explicitly:

stash pull-request origin/feature_branch master