User Friendly Error Message on git/svn Error

[JamesDrummond]

When a user tries to push to a remote repository with git or svn the message just tells the user it fails to unauthorized. We should include a popup windows that tells the user that it failed due to credentials but also direct them to docs to get additional information.

For git oauth fail we direct to /docs/user-guide/git-svn/index.html#github-oauth.

For git ssh fail we direct to /docs/user-guide/git-svn/index.html#adding-ssh-public-key-to-repository-account.

For svn login fail we direct to /docs/user-guide/git-svn/index.html#svn-using-usernamepassword

Consider creating file database with doc links such as yaml or json. This will allow us to globally change doc paths and verify that all links work. For example a yaml database file with link to svn login fail could be something like docs-gitsvn: "/docs/user-guide/git-svn/index.html" and docs-gitsvn-svn-fail: "svn-using-usernamepassword"

Referenced issue #968

[JamesDrummond]

Updated above.

[JamesDrummond]

No longer required per changes to eclipse-che/che#2804 .